From c0048c7c4d7418c45edbe8a0f65b89b6611ce65e Mon Sep 17 00:00:00 2001 From: Sebastiaan Huber Date: Wed, 9 May 2018 12:48:11 +0200 Subject: [PATCH] Add the input helper xml files for v6.0, v.6.1 and v6.2 --- .../calculations/helpers/INPUT_PW-6.0.xml | 2947 ++++++++++++++++ .../calculations/helpers/INPUT_PW-6.1.xml | 2964 ++++++++++++++++ .../calculations/helpers/INPUT_PW-6.2.xml | 2992 +++++++++++++++++ .../calculations/helpers/__init__.py | 2 +- 4 files changed, 8904 insertions(+), 1 deletion(-) create mode 100644 aiida_quantumespresso/calculations/helpers/INPUT_PW-6.0.xml create mode 100644 aiida_quantumespresso/calculations/helpers/INPUT_PW-6.1.xml create mode 100644 aiida_quantumespresso/calculations/helpers/INPUT_PW-6.2.xml diff --git a/aiida_quantumespresso/calculations/helpers/INPUT_PW-6.0.xml b/aiida_quantumespresso/calculations/helpers/INPUT_PW-6.0.xml new file mode 100644 index 000000000..798e9d66f --- /dev/null +++ b/aiida_quantumespresso/calculations/helpers/INPUT_PW-6.0.xml @@ -0,0 +1,2947 @@ + + + + + + + + +Input data format: { } = optional, [ ] = it depends, | = or + +All quantities whose dimensions are not explicitly specified are in +RYDBERG ATOMIC UNITS. Charge is "number" charge (i.e. not multiplied +by e); potentials are in energy units (i.e. they are multiplied by e). + +BEWARE: TABS, DOS <CR><LF> CHARACTERS ARE POTENTIAL SOURCES OF TROUBLE + +Comment lines in namelists can be introduced by a "!", exactly as in +fortran code. Comments lines in cards can be introduced by +either a "!" or a "#" character in the first position of a line. +Do not start any line in cards with a "/" character. + + +Structure of the input data: +=============================================================================== + +&CONTROL + ... +/ + +&SYSTEM + ... +/ + +&ELECTRONS + ... +/ + +[ &IONS + ... + / ] + +[ &CELL + ... + / ] + +ATOMIC_SPECIES + X Mass_X PseudoPot_X + Y Mass_Y PseudoPot_Y + Z Mass_Z PseudoPot_Z + +ATOMIC_POSITIONS { alat | bohr | crystal | angstrom | crystal_sg } + X 0.0 0.0 0.0 {if_pos(1) if_pos(2) if_pos(3)} + Y 0.5 0.0 0.0 + Z O.0 0.2 0.2 + +K_POINTS { tpiba | automatic | crystal | gamma | tpiba_b | crystal_b | tpiba_c | crystal_c } +if (gamma) + nothing to read +if (automatic) + nk1, nk2, nk3, k1, k2, k3 +if (not automatic) + nks + xk_x, xk_y, xk_z, wk + +[ CELL_PARAMETERS { alat | bohr | angstrom } + v1(1) v1(2) v1(3) + v2(1) v2(2) v2(3) + v3(1) v3(2) v3(3) ] + +[ OCCUPATIONS + f_inp1(1) f_inp1(2) f_inp1(3) ... f_inp1(10) + f_inp1(11) f_inp1(12) ... f_inp1(nbnd) + [ f_inp2(1) f_inp2(2) f_inp2(3) ... f_inp2(10) + f_inp2(11) f_inp2(12) ... f_inp2(nbnd) ] ] + +[ CONSTRAINTS + nconstr { constr_tol } + constr_type(.) constr(1,.) constr(2,.) [ constr(3,.) constr(4,.) ] { constr_target(.) } ] + +[ ATOMIC_FORCES + label_1 Fx(1) Fy(1) Fz(1) + ..... + label_n Fx(n) Fy(n) Fz(n) ] + + + + 'scf' + + + +A string describing the task to be performed. Options are: + + + + + + + + + + + + + + + + +(vc = variable-cell). + + + + + ' ' + + +reprinted on output. + + + + 'low' + + + +Currently two verbosity levels are implemented: + + + + + + +'debug' and 'medium' have the same effect as 'high'; +'default' and 'minimal' as 'low' + + + + + 'from_scratch' + + + Available options are: + + +From scratch. This is the normal way to perform a PWscf calculation + + +From previous interrupted run. Use this switch only if you want to +continue an interrupted calculation, not to start a new one, or to +perform non-scf calculations. Works only if the calculation was +cleanly stopped using variable max_seconds, or by user request +with an "exit file" (i.e.: create a file "prefix".EXIT, in directory +"outdir"; see variables prefix, outdir). Overrides startingwfc +and startingpot. + + + + + .FALSE. + + +This flag controls the way wavefunctions are stored to disk : + +.TRUE. collect wavefunctions from all processors, store them + into the output data directory "outdir"/"prefix".save, + one wavefunction per k-point in subdirs K000001/, + K000001/, etc.. Use this if you want wavefunctions + to be readable on a different number of processors. + +.FALSE. do not collect wavefunctions, leave them in temporary + local files (one per processor). The resulting format + will be readable only by jobs running on the same + number of processors and pools. Requires less I/O + than the previous case. + +Note that this flag has no effect on reading, only on writing. + + + + +number of molecular-dynamics or structural optimization steps +performed in this run + + +1 if calculation == 'scf', 'nscf', 'bands'; +50 for the other cases + + + + write only at convergence + + +band energies are written every iprint iterations + + + + .false. + + +calculate stress. It is set to .TRUE. automatically if +calculation == 'vc-md' or 'vc-relax' + + + + +calculate forces. It is set to .TRUE. automatically if +calculation == 'relax','md','vc-md' + + + + 20.D0 + + +time step for molecular dynamics, in Rydberg atomic units +(1 a.u.=4.8378 * 10^-17 s : beware, the CP code uses + Hartree atomic units, half that much!!!) + + + + +value of the ESPRESSO_TMPDIR environment variable if set; +current directory ('./') otherwise + + +input, temporary, output files are found in this directory, +see also wfcdir + + + + same as outdir + + +This directory specifies where to store files generated by +each processor (*.wfc{N}, *.igk{N}, etc.). Useful for +machines without a parallel file system: set wfcdir to +a local file system, while outdir should be a parallel +or networkfile system, visible to all processors. Beware: +in order to restart from interrupted runs, or to perform +further calculations using the produced data files, you +may need to copy files to outdir. Works only for pw.x. + + + + 'pwscf' + + +prepended to input/output filenames: +prefix.wfc, prefix.rho, etc. + + + + .true. + + +If .false. a subdirectory for each k_point is not opened +in the "prefix".save directory; Kohn-Sham eigenvalues are +stored instead in a single file for all k-points. Currently +doesn't work together with wf_collect + + + + 1.D+7, or 150 days, i.e. no time limit + + +Jobs stops after max_seconds CPU time. Use this option +in conjunction with option restart_mode if you need to +split a job too long to complete into shorter jobs that +fit into your batch queues. + + + + 1.0D-4 + + +Convergence threshold on total energy (a.u) for ionic +minimization: the convergence criterion is satisfied +when the total energy changes less than etot_conv_thr +between two consecutive scf steps. Note that etot_conv_thr +is extensive, like the total energy. +See also forc_conv_thr - both criteria must be satisfied + + + + 1.0D-3 + + +Convergence threshold on forces (a.u) for ionic minimization: +the convergence criterion is satisfied when all components of +all forces are smaller than forc_conv_thr. +See also etot_conv_thr - both criteria must be satisfied + + + + see below + + + +Specifies the amount of disk I/O activity: + + +save all data to disk at each SCF step + + +save wavefunctions at each SCF step unless +there is a single k-point per process (in which +case the behavior is the same as 'low') + + +store wfc in memory, save only at the end + + +do not save anything, not even at the end +('scf', 'nscf', 'bands' calculations; some data +may be written anyway for other calculations) + + +Default is 'low' for the scf case, 'medium' otherwise. +Note that the needed RAM increases as disk I/O decreases! +It is no longer needed to specify 'high' in order to be able +to restart from an interrupted calculation (see restart_mode) +but you cannot restart in disk_io=='none' + + + + + +value of the $ESPRESSO_PSEUDO environment variable if set; +'$HOME/espresso/pseudo/' otherwise + + +directory containing pseudopotential files + + + + .FALSE. + + +If .TRUE. a saw-like potential simulating an electric field +is added to the bare ionic potential. See variables edir, +eamp, emaxpos, eopreg for the form and size of +the added potential. + + + + .FALSE. + + +If .TRUE. and tefield==.TRUE. a dipole correction is also +added to the bare ionic potential - implements the recipe +of L. Bengtsson, PRB 59, 12301 (1999). See variables edir, +emaxpos, eopreg for the form of the correction. Must +be used ONLY in a slab geometry, for surface calculations, +with the discontinuity FALLING IN THE EMPTY SPACE. + + + + .FALSE. + + +If .TRUE. a homogeneous finite electric field described +through the modern theory of the polarization is applied. +This is different from tefield == .true. ! + + + + 1 + + +In the case of a finite electric field ( lelfield == .TRUE. ) +it defines the number of iterations for converging the +wavefunctions in the electric field Hamiltonian, for each +external iteration on the charge density + + + + .FALSE. + + +If .TRUE. perform orbital magnetization calculation. +If finite electric field is applied (lelfield==.true.) +only Kubo terms are computed +[for details see New J. Phys. 12, 053032 (2010)]. +The type of calculation is 'nscf' and should be performed +on an automatically generated uniform grid of k points. +Works ONLY with norm-conserving pseudopotentials. + + + + .FALSE. + + +If .TRUE. perform a Berry phase calculation. +See the header of PW/src/bp_c_phase.f90 for documentation. + + + + +For Berry phase calculation: direction of the k-point +strings in reciprocal space. Allowed values: 1, 2, 3 +1=first, 2=second, 3=third reciprocal lattice vector +For calculations with finite electric fields +(lelfield==.true.) "gdir" is the direction of the field. + + + + +For Berry phase calculation: number of k-points to be +calculated along each symmetry-reduced string. +The same for calculation with finite electric fields +(lelfield==.true.). + + + + fcp_mu + + .FALSE. + + +If .TRUE. perform a constant bias potential (constant-mu) calculation +for a static system with ESM method. See the header of PW/src/fcp.f90 +for documentation. + +NB: +- The total energy displayed in 'prefix.out' includes the potentiostat + contribution (-mu*N). +- calculation must be 'relax'. +- assume_isolated = 'esm' and esm_bc = 'bc2' or 'bc3' must be set + in SYSTEM namelist. + + + + .FALSE. + + zmon, realxz, block, block_1, block_2, block_height + + +In the case of charged cells (tot_charge .ne. 0) setting monopole = .TRUE. +represents the counter charge (i.e. -tot_charge) not by a homogenous +background charge but with a charged plate, which is placed at zmon +(see below). Details of the monopole potential can be found in +T. Brumme, M. Calandra, F. Mauri; PRB 89, 245406 (2014). +Note, that in systems which are not symmetric with respect to the plate, +one needs to enable the dipole correction! (dipfield=.true.). +Currently, symmetry can be used with monopole=.true. but carefully check +that no symmetry is included which maps z to -z even if in principle one +could still use them for symmetric systems (i.e. no dipole correction). +For nosym=.false. verbosity is set to 'high'. + + + + + + REQUIRED + + + Bravais-lattice index. If ibrav /= 0, specify EITHER + [ celldm(1)-celldm(6) ] OR [ A, B, C, cosAB, cosAC, cosBC ] + but NOT both. The lattice parameter "alat" is set to + alat = celldm(1) (in a.u.) or alat = A (in Angstrom); + see below for the other parameters. + For ibrav=0 specify the lattice vectors in CELL_PARAMETERS, + optionally the lattice parameter alat = celldm(1) (in a.u.) + or = A (in Angstrom), or else it is taken from CELL_PARAMETERS + +ibrav structure celldm(2)-celldm(6) + or: b,c,cosab,cosac,cosbc + 0 free + crystal axis provided in input: see card CELL_PARAMETERS + + 1 cubic P (sc) + v1 = a(1,0,0), v2 = a(0,1,0), v3 = a(0,0,1) + + 2 cubic F (fcc) + v1 = (a/2)(-1,0,1), v2 = (a/2)(0,1,1), v3 = (a/2)(-1,1,0) + + 3 cubic I (bcc) + v1 = (a/2)(1,1,1), v2 = (a/2)(-1,1,1), v3 = (a/2)(-1,-1,1) + + 4 Hexagonal and Trigonal P celldm(3)=c/a + v1 = a(1,0,0), v2 = a(-1/2,sqrt(3)/2,0), v3 = a(0,0,c/a) + + 5 Trigonal R, 3fold axis c celldm(4)=cos(alpha) + The crystallographic vectors form a three-fold star around + the z-axis, the primitive cell is a simple rhombohedron: + v1 = a(tx,-ty,tz), v2 = a(0,2ty,tz), v3 = a(-tx,-ty,tz) + where c=cos(alpha) is the cosine of the angle alpha between + any pair of crystallographic vectors, tx, ty, tz are: + tx=sqrt((1-c)/2), ty=sqrt((1-c)/6), tz=sqrt((1+2c)/3) + -5 Trigonal R, 3fold axis <111> celldm(4)=cos(alpha) + The crystallographic vectors form a three-fold star around + <111>. Defining a' = a/sqrt(3) : + v1 = a' (u,v,v), v2 = a' (v,u,v), v3 = a' (v,v,u) + where u and v are defined as + u = tz - 2*sqrt(2)*ty, v = tz + sqrt(2)*ty + and tx, ty, tz as for case ibrav=5 + Note: if you prefer x,y,z as axis in the cubic limit, + set u = tz + 2*sqrt(2)*ty, v = tz - sqrt(2)*ty + See also the note in Modules/latgen.f90 + + 6 Tetragonal P (st) celldm(3)=c/a + v1 = a(1,0,0), v2 = a(0,1,0), v3 = a(0,0,c/a) + + 7 Tetragonal I (bct) celldm(3)=c/a + v1=(a/2)(1,-1,c/a), v2=(a/2)(1,1,c/a), v3=(a/2)(-1,-1,c/a) + + 8 Orthorhombic P celldm(2)=b/a + celldm(3)=c/a + v1 = (a,0,0), v2 = (0,b,0), v3 = (0,0,c) + + 9 Orthorhombic base-centered(bco) celldm(2)=b/a + celldm(3)=c/a + v1 = (a/2, b/2,0), v2 = (-a/2,b/2,0), v3 = (0,0,c) + -9 as 9, alternate description + v1 = (a/2,-b/2,0), v2 = (a/2, b/2,0), v3 = (0,0,c) + + 10 Orthorhombic face-centered celldm(2)=b/a + celldm(3)=c/a + v1 = (a/2,0,c/2), v2 = (a/2,b/2,0), v3 = (0,b/2,c/2) + + 11 Orthorhombic body-centered celldm(2)=b/a + celldm(3)=c/a + v1=(a/2,b/2,c/2), v2=(-a/2,b/2,c/2), v3=(-a/2,-b/2,c/2) + + 12 Monoclinic P, unique axis c celldm(2)=b/a + celldm(3)=c/a, + celldm(4)=cos(ab) + v1=(a,0,0), v2=(b*cos(gamma),b*sin(gamma),0), v3 = (0,0,c) + where gamma is the angle between axis a and b. +-12 Monoclinic P, unique axis b celldm(2)=b/a + celldm(3)=c/a, + celldm(5)=cos(ac) + v1 = (a,0,0), v2 = (0,b,0), v3 = (c*cos(beta),0,c*sin(beta)) + where beta is the angle between axis a and c + + 13 Monoclinic base-centered celldm(2)=b/a + celldm(3)=c/a, + celldm(4)=cos(ab) + v1 = ( a/2, 0, -c/2), + v2 = (b*cos(gamma), b*sin(gamma), 0), + v3 = ( a/2, 0, c/2), + where gamma is the angle between axis a and b + + 14 Triclinic celldm(2)= b/a, + celldm(3)= c/a, + celldm(4)= cos(bc), + celldm(5)= cos(ac), + celldm(6)= cos(ab) + v1 = (a, 0, 0), + v2 = (b*cos(gamma), b*sin(gamma), 0) + v3 = (c*cos(beta), c*(cos(alpha)-cos(beta)cos(gamma))/sin(gamma), + c*sqrt( 1 + 2*cos(alpha)cos(beta)cos(gamma) + - cos(alpha)^2-cos(beta)^2-cos(gamma)^2 )/sin(gamma) ) + where alpha is the angle between axis b and c + beta is the angle between axis a and c + gamma is the angle between axis a and b + + + + + + ibrav + + +Crystallographic constants - see the ibrav variable. +Specify either these OR A,B,C,cosAB,cosBC,cosAC NOT both. +Only needed values (depending on "ibrav") must be specified +alat = celldm(1) is the lattice parameter "a" (in BOHR) +If ibrav==0, only celldm(1) is used if present; +cell vectors are read from card CELL_PARAMETERS + + + + + + + + + + + + + + + + + ibrav + + +Traditional crystallographic constants: + + a,b,c in ANGSTROM + cosAB = cosine of the angle between axis a and b (gamma) + cosAC = cosine of the angle between axis a and c (beta) + cosBC = cosine of the angle between axis b and c (alpha) + +The axis are chosen according to the value of ibrav. +Specify either these OR celldm but NOT both. +Only needed values (depending on ibrav) must be specified. + +The lattice parameter alat = A (in ANGSTROM ). + +If ibrav == 0, only A is used if present, and +cell vectors are read from card CELL_PARAMETERS. + + + + + REQUIRED + + +number of atoms in the unit cell (ALL atoms, except if +space_group is set, in which case, INEQUIVALENT atoms) + + + + REQUIRED + + +number of types of atoms in the unit cell + + + + +for an insulator, nbnd = number of valence bands +(nbnd = # of electrons /2); +
for a metal, 20% more (minimum 4 more) + + +Number of electronic states (bands) to be calculated. +Note that in spin-polarized calculations the number of +k-point, not the number of bands per k-point, is doubled + + + + 0.0 + + +Total charge of the system. Useful for simulations with charged cells. +By default the unit cell is assumed to be neutral (tot_charge=0). +tot_charge=+1 means one electron missing from the system, +tot_charge=-1 means one additional electron, and so on. + +In a periodic calculation a compensating jellium background is +inserted to remove divergences if the cell is not neutral. + + + + -1 [unspecified] + + +Total majority spin charge - minority spin charge. +Used to impose a specific total electronic magnetization. +If unspecified then tot_magnetization variable is ignored and +the amount of electronic magnetization is determined during +the self-consistent cycle. + + + + +Starting spin polarization on atomic type 'i' in a spin +polarized calculation. Values range between -1 (all spins +down for the valence electrons of atom type 'i') to 1 +(all spins up). Breaks the symmetry and provides a starting +point for self-consistency. The default value is zero, BUT a +value MUST be specified for AT LEAST one atomic type in spin +polarized calculations, unless you constrain the magnetization +(see tot_magnetization and constrained_magnetization). +Note that if you start from zero initial magnetization, you +will invariably end up in a nonmagnetic (zero magnetization) +state. If you want to start from an antiferromagnetic state, +you may need to define two different atomic species +corresponding to sublattices of the same atomic type. +starting_magnetization is ignored if you are performing a +non-scf calculation, if you are restarting from a previous +run, or restarting from an interrupted run. +If you fix the magnetization with tot_magnetization, +you should not specify starting_magnetization. +In the spin-orbit case starting with zero +starting_magnetization on all atoms imposes time reversal +symmetry. The magnetization is never calculated and +kept zero (the internal variable domag is .FALSE.). + + + + REQUIRED + + +kinetic energy cutoff (Ry) for wavefunctions + + + + 4 * ecutwfc + + +Kinetic energy cutoff (Ry) for charge density and potential +For norm-conserving pseudopotential you should stick to the +default value, you can reduce it by a little but it will +introduce noise especially on forces and stress. +If there are ultrasoft PP, a larger value than the default is +often desirable (ecutrho = 8 to 12 times ecutwfc, typically). +PAW datasets can often be used at 4*ecutwfc, but it depends +on the shape of augmentation charge: testing is mandatory. +The use of gradient-corrected functional, especially in cells +with vacuum, or for pseudopotential without non-linear core +correction, usually requires an higher values of ecutrho +to be accurately converged. + + + + ecutrho + + +Kinetic energy cutoff (Ry) for the exact exchange operator in +EXX type calculations. By default this is the same as ecutrho +but in some EXX calculations significant speed-up can be found +by reducing ecutfock, at the expense of some loss in accuracy. +Must be .gt. ecutwfc. Not implemented for stress calculation. +Use with care, especially in metals where it may give raise +to instabilities. + + + + + + + + + + +Three-dimensional FFT mesh (hard grid) for charge +density (and scf potential). If not specified +the grid is calculated based on the cutoff for +charge density (see also ecutrho) +Note: you must specify all three dimensions for this setting to +be used. + + + + + + + + + + +Three-dimensional mesh for wavefunction FFT and for the smooth +part of charge density ( smooth grid ). +Coincides with nr1, nr2, nr3 if ecutrho = 4 * ecutwfc ( default ) +Note: you must specify all three dimensions for this setting to +be used. + + + + .FALSE. + + +if (.TRUE.) symmetry is not used, which means that: + +- if a list of k points is provided in input, it is used + "as is": symmetry-inequivalent k-points are not generated, + and the charge density is not symmetrized; + +- if a uniform (Monkhorst-Pack) k-point grid is provided in + input, it is expanded to cover the entire Brillouin Zone, + irrespective of the crystal symmetry. + Time reversal symmetry is assumed so k and -k are considered + as equivalent unless noinv=.true. is specified. + +A careful usage of this option can be advantageous: +- in low-symmetry large cells, if you cannot afford a k-point + grid with the correct symmetry +- in MD simulations +- in calculations for isolated atoms + + + + .FALSE. + + +if (.TRUE.) symmetry is not used, and k points are +forced to have the symmetry of the Bravais lattice; +an automatically generated Monkhorst-Pack grid will contain +all points of the grid over the entire Brillouin Zone, +plus the points rotated by the symmetries of the Bravais +lattice which were not in the original grid. The same +applies if a k-point list is provided in input instead +of a Monkhorst-Pack grid. Time reversal symmetry is assumed +so k and -k are equivalent unless noinv=.true. is specified. +This option differs from nosym because it forces k-points +in all cases to have the full symmetry of the Bravais lattice +(not all uniform grids have such property!) + + + + .FALSE. + + +if (.TRUE.) disable the usage of k => -k symmetry +(time reversal) in k-point generation + + + + .FALSE. + + +if (.TRUE.) disable the usage of magnetic symmetry operations +that consist in a rotation + time reversal. + + + + .FALSE. + + +if (.TRUE.) force the symmetry group to be symmorphic by disabling +symmetry operations having an associated fractionary translation + + + + .FALSE. + + +if (.TRUE.) do not discard symmetry operations with an +associated fractionary translation that does not send the +real-space FFT grid into itself. These operations are +incompatible with real-space symmetrization but not with the +new G-space symmetrization. BEWARE: do not use for phonons +and for hybrid functionals! Both still use symmetrization +in real space. + + + + + Available options are: + + +gaussian smearing for metals; +see variables smearing and degauss + + +especially suited for calculation of DOS +(see P.E. Bloechl, PRB 49, 16223 (1994)). +Requires uniform grid of k-points, +automatically generated (see below). +Not suitable (because not variational) for +force/optimization/dynamics calculations. + + +for insulators with a gap + + +The occupation are read from input file, +card OCCUPATIONS. Option valid only for a +single k-point, requires nbnd to be set +in input. Occupations should be consistent +with the value of tot_charge. + + + + + .FALSE. + + +This flag is used for isolated atoms (nat=1) together with +occupations='from_input'. If it is .TRUE., the wavefunctions +are ordered as the atomic starting wavefunctions, independently +from their eigenvalue. The occupations indicate which atomic +states are filled. + +The order of the states is written inside the UPF pseudopotential file. +In the scalar relativistic case: +S -> l=0, m=0 +P -> l=1, z, x, y +D -> l=2, r^2-3z^2, xz, yz, xy, x^2-y^2 + +In the noncollinear magnetic case (with or without spin-orbit), +each group of states is doubled. For instance: +P -> l=1, z, x, y for spin up, l=1, z, x, y for spin down. +Up and down is relative to the direction of the starting +magnetization. + +In the case with spin-orbit and time-reversal +(starting_magnetization=0.0) the atomic wavefunctions are +radial functions multiplied by spin-angle functions. +For instance: +P -> l=1, j=1/2, m_j=-1/2,1/2. l=1, j=3/2, + m_j=-3/2, -1/2, 1/2, 3/2. + +In the magnetic case with spin-orbit the atomic wavefunctions +can be forced to be spin-angle functions by setting +starting_spin_angle to .TRUE.. + + + + .FALSE. + + +In the spin-orbit case when domag=.TRUE., by default, +the starting wavefunctions are initialized as in scalar +relativistic noncollinear case without spin-orbit. + +By setting starting_spin_angle=.TRUE. this behaviour can +be changed and the initial wavefunctions are radial +functions multiplied by spin-angle functions. + +When domag=.FALSE. the initial wavefunctions are always +radial functions multiplied by spin-angle functions +independently from this flag. + +When lspinorb is .FALSE. this flag is not used. + + + + 0.D0 Ry + + +value of the gaussian spreading (Ry) for brillouin-zone +integration in metals. + + + + 'gaussian' + + + +Available options are: + + +ordinary Gaussian spreading (Default) + + +Methfessel-Paxton first-order spreading +(see PRB 40, 3616 (1989)). + + +Marzari-Vanderbilt cold smearing +(see PRL 82, 3296 (1999)) + + +smearing with Fermi-Dirac function + + + + + 1 + + +nspin = 1 : non-polarized calculation (default) + +nspin = 2 : spin-polarized calculation, LSDA + (magnetization along z axis) + +nspin = 4 : spin-polarized calculation, noncollinear + (magnetization in generic direction) + DO NOT specify nspin in this case; + specify noncolin=.TRUE. instead + + + + .false. + + +if .true. the program will perform a noncollinear calculation. + + + + 0.0 + + q2sigma + + + + 0.0 + + q2sigma + + + + 0.1 + + +ecfixed, qcutz, q2sigma: parameters for modified functional to be +used in variable-cell molecular dynamics (or in stress calculation). +"ecfixed" is the value (in Rydberg) of the constant-cutoff; +"qcutz" and "q2sigma" are the height and the width (in Rydberg) +of the energy step for reciprocal vectors whose square modulus +is greater than "ecfixed". In the kinetic energy, G^2 is +replaced by G^2 + qcutz * (1 + erf ( (G^2 - ecfixed)/q2sigma) ) +See: M. Bernasconi et al, J. Phys. Chem. Solids 56, 501 (1995) + + + + read from pseudopotential files + + +Exchange-correlation functional: eg 'PBE', 'BLYP' etc +See Modules/funct.f90 for allowed values. +Overrides the value read from pseudopotential files. +Use with care and if you know what you are doing! + + + + it depends on the specified functional + + +Fraction of EXX for hybrid functional calculations. In the case of +input_dft='PBE0', the default value is 0.25, while for input_dft='B3LYP' +the exx_fraction default value is 0.20. + + + + 0.106 + + +screening_parameter for HSE like hybrid functionals. +See J. Chem. Phys. 118, 8207 (2003) +and J. Chem. Phys. 124, 219906 (2006) for more informations. + + + + 'gygi-baldereschi' + + + +Specific for EXX. It selects the kind of approach to be used +for treating the Coulomb potential divergencies at small q vectors. + + appropriate for cubic and quasi-cubic supercells + + appropriate for cubic and quasi-cubic supercells + + appropriate for strongly anisotropic supercells, see also ecutvcut. + + sets Coulomb potential at G,q=0 to 0.0 (required for GAU-PBE) + + + + + .true. + + +Specific for EXX. If .true., extrapolate the G=0 term of the +potential (see README in examples/EXX_example for more) +Set this to .false. for GAU-PBE. + + + + 0.0 Ry + + exxdiv_treatment + + +Reciprocal space cutoff for correcting Coulomb potential +divergencies at small q vectors. + + + + + + + + + + +Three-dimensional mesh for q (k1-k2) sampling of +the Fock operator (EXX). Can be smaller than +the number of k-points. + +Currently this defaults to the size of the k-point mesh used. +In QE =< 5.0.2 it defaulted to nqx1=nqx2=nqx3=1. + + + + .FALSE. + + +DFT+U (formerly known as LDA+U) currently works only for +a few selected elements. Modify Modules/set_hubbard_l.f90 and +PW/src/tabd.f90 if you plan to use DFT+U with an element that +is not configured there. + + +Specify lda_plus_u = .TRUE. to enable DFT+U calculations +See: Anisimov, Zaanen, and Andersen, PRB 44, 943 (1991); + Anisimov et al., PRB 48, 16929 (1993); + Liechtenstein, Anisimov, and Zaanen, PRB 52, R5467 (1994). +You must specify, for each species with a U term, the value of +U and (optionally) alpha, J of the Hubbard model (all in eV): +see lda_plus_u_kind, Hubbard_U, Hubbard_alpha, Hubbard_J + + + + 0 + + +Specifies the type of DFT+U calculation: + + 0 simplified version of Cococcioni and de Gironcoli, + PRB 71, 035105 (2005), using Hubbard_U + + 1 rotationally invariant scheme of Liechtenstein et al., + using Hubbard_U and Hubbard_J + + + + 0.D0 for all species + + +Hubbard_U(i): U parameter (eV) for species i, DFT+U calculation + + + + 0.D0 for all species + + +Hubbard_J0(i): J0 parameter (eV) for species i, DFT+U+J calculation, +see PRB 84, 115108 (2011) for details. + + + + 0.D0 for all species + + +Hubbard_alpha(i) is the perturbation (on atom i, in eV) +used to compute U with the linear-response method of +Cococcioni and de Gironcoli, PRB 71, 35105 (2005) +(only for lda_plus_u_kind=0) + + + + 0.D0 for all species + + +Hubbard_beta(i) is the perturbation (on atom i, in eV) +used to compute J0 with the linear-response method of +Cococcioni and de Gironcoli, PRB 71, 35105 (2005) +(only for lda_plus_u_kind=0). See also +PRB 84, 115108 (2011). + + + + 0.D0 for all species + + +Hubbard_J(i,ityp): J parameters (eV) for species ityp, +used in DFT+U calculations (only for lda_plus_u_kind=1) +For p orbitals: J = Hubbard_J(1,ityp); +For d orbitals: J = Hubbard_J(1,ityp), B = Hubbard_J(2,ityp); +For f orbitals: J = Hubbard_J(1,ityp), E2 = Hubbard_J(2,ityp), + E3= Hubbard_J(3,ityp). +If B or E2 or E3 are not specified or set to 0 they will be +calculated from J using atomic ratios. + + + + -1.d0 that means NOT SET + + +In the first iteration of an DFT+U run it overwrites +the m-th eigenvalue of the ns occupation matrix for the +ispin component of atomic species I. Leave unchanged +eigenvalues that are not set. This is useful to suggest +the desired orbital occupations when the default choice +takes another path. + + + + 'atomic' + + + +Only active when lda_plus_U is .true., specifies the type +of projector on localized orbital to be used in the DFT+U +scheme. + +Currently available choices: + + use atomic wfc's (as they are) to build the projector + + use Lowdin orthogonalized atomic wfc's + + +Lowdin normalization of atomic wfc. Keep in mind: +atomic wfc are not orthogonalized in this case. +This is a "quick and dirty" trick to be used when +atomic wfc from the pseudopotential are not +normalized (and thus produce occupation whose +value exceeds unity). If orthogonalized wfc are +not needed always try 'atomic' first. + + +use the information from file "prefix".atwfc that must +have been generated previously, for instance by pmw.x +(see PP/src/poormanwannier.f90 for details). + + +use the pseudopotential projectors. The charge density +outside the atomic core radii is excluded. +N.B.: for atoms with +U, a pseudopotential with the +all-electron atomic wavefunctions is required (i.e., +as generated by ld1.x with lsave_wfc flag). + + +NB: forces and stress currently implemented only for the +'atomic' and 'pseudo' choice. + + + + + +The direction of the electric field or dipole correction is +parallel to the bg(:,edir) reciprocal lattice vector, so the +potential is constant in planes defined by FFT grid points; +edir = 1, 2 or 3. Used only if tefield is .TRUE. + + + + 0.5D0 + + +Position of the maximum of the saw-like potential along crystal +axis edir, within the unit cell (see below), 0 < emaxpos < 1 +Used only if tefield is .TRUE. + + + + 0.1D0 + + +Zone in the unit cell where the saw-like potential decreases. +( see below, 0 < eopreg < 1 ). Used only if tefield is .TRUE. + + + + 0.001 a.u. + + +Amplitude of the electric field, in ***Hartree*** a.u.; +1 a.u. = 51.4220632*10^10 V/m. Used only if tefield==.TRUE. +The saw-like potential increases with slope eamp in the +region from (emaxpos+eopreg-1) to (emaxpos), then decreases +to 0 until (emaxpos+eopreg), in units of the crystal +vector edir. Important: the change of slope of this +potential must be located in the empty region, or else +unphysical forces will result. + + + + +The angle expressed in degrees between the initial +magnetization and the z-axis. For noncollinear calculations +only; index i runs over the atom types. + + + + +The angle expressed in degrees between the projection +of the initial magnetization on x-y plane and the x-axis. +For noncollinear calculations only. + + + + lambda, fixed_magnetization + + 'none' + + + +Used to perform constrained calculations in magnetic systems. +Currently available choices: + + +no constraint + + +total magnetization is constrained by +adding a penalty functional to the total energy: + +LAMBDA * SUM_{i} ( magnetization(i) - fixed_magnetization(i) )**2 + +where the sum over i runs over the three components of +the magnetization. Lambda is a real number (see below). +Noncolinear case only. Use tot_magnetization for LSDA + + +atomic magnetization are constrained to the defined +starting magnetization adding a penalty: + +LAMBDA * SUM_{i,itype} ( magnetic_moment(i,itype) - mcons(i,itype) )**2 + +where i runs over the cartesian components (or just z +in the collinear case) and itype over the types (1-ntype). +mcons(:,:) array is defined from starting_magnetization, +(and angle1, angle2 in the non-collinear case). lambda is +a real number + + +the angle theta of the total magnetization +with the z axis (theta = fixed_magnetization(3)) +is constrained: + +LAMBDA * ( arccos(magnetization(3)/mag_tot) - theta )**2 + +where mag_tot is the modulus of the total magnetization. + + +not all the components of the atomic +magnetic moment are constrained but only the cosine +of angle1, and the penalty functional is: + +LAMBDA * SUM_{itype} ( mag_mom(3,itype)/mag_mom_tot - cos(angle1(ityp)) )**2 + + +N.B.: symmetrization may prevent to reach the desired orientation +of the magnetization. Try not to start with very highly symmetric +configurations or use the nosym flag (only as a last remedy) + + + + + constrained_magnetization + + 0.d0 + + +total magnetization vector (x,y,z components) to be kept +fixed when constrained_magnetization=='total' + + + + constrained_magnetization + + 1.d0 + + +parameter used for constrained_magnetization calculations +N.B.: if the scf calculation does not converge, try to reduce lambda + to obtain convergence, then restart the run with a larger lambda + + + + 100 + + +Number of iterations after which the program +writes all the atomic magnetic moments. + + + + +if .TRUE. the noncollinear code can use a pseudopotential with +spin-orbit. + + + + 'none' + + + +Used to perform calculation assuming the system to be +isolated (a molecule or a cluster in a 3D supercell). + +Currently available choices: + + +(default): regular periodic calculation w/o any correction. + + +the Makov-Payne correction to the +total energy is computed. An estimate of the vacuum +level is also calculated so that eigenvalues can be +properly aligned. ONLY FOR CUBIC SYSTEMS (ibrav=1,2,3). +Theory: G.Makov, and M.C.Payne, + "Periodic boundary conditions in ab initio + calculations" , PRB 51, 4014 (1995). + + +Martyna-Tuckerman correction +to both total energy and scf potential. Adapted from: +G.J. Martyna, and M.E. Tuckerman, +"A reciprocal space based method for treating long +range interactions in ab-initio and force-field-based +calculation in clusters", J.Chem.Phys. 110, 2810 (1999). + + +Effective Screening Medium Method. +For polarized or charged slab calculation, embeds +the simulation cell within an effective semi- +infinite medium in the perpendicular direction +(along z). Embedding regions can be vacuum or +semi-infinite metal electrodes (use 'esm_bc' to +choose boundary conditions). If between two +electrodes, an optional electric field +('esm_efield') may be applied. Method described in +M. Otani and O. Sugino, "First-principles calculations +of charged surfaces and interfaces: A plane-wave +nonrepeated slab approach", PRB 73, 115407 (2006). + +NB: + - Two dimensional (xy plane) average charge density + and electrostatic potentials are printed out to + 'prefix.esm1'. + + - Requires cell with a_3 lattice vector along z, + normal to the xy plane, with the slab centered + around z=0. Also requires symmetry checking to be + disabled along z, either by setting nosym = .TRUE. + or by very slight displacement (i.e., 5e-4 a.u.) + of the slab along z. + +See esm_bc, esm_efield, esm_w, esm_nfit. + + + + + assume_isolated + + 'pbc' + + + +If assume_isolated = 'esm', determines the boundary +conditions used for either side of the slab. + +Currently available choices: + + (default): regular periodic calculation (no ESM). + + Vacuum-slab-vacuum (open boundary conditions). + + +Metal-slab-metal (dual electrode configuration). +See also esm_efield. + + Vacuum-slab-metal + + + + + assume_isolated + + 0.d0 + + +If assume_isolated = 'esm', determines the position offset +[in a.u.] of the start of the effective screening region, +measured relative to the cell edge. (ESM region begins at +z = +/- [L_z/2 + esm_w] ). + + + + assume_isolated + + 0.d0 + + +If assume_isolated = 'esm' and esm_bc = 'bc2', gives the +magnitude of the electric field [Ry/a.u.] to be applied +between semi-infinite ESM electrodes. + + + + assume_isolated + + 4 + + +If assume_isolated = 'esm', gives the number of z-grid points +for the polynomial fit along the cell edge. + + + + lfcpopt + + 0.d0 + + +If lfcpopt = .TRUE., gives the target Fermi energy [Ry]. One can start +with appropriate total charge of the system by giving 'tot_charge'. + + + + 'none' + + +london_s6, london_rcut, london_c6, london_rvdw, ts_vdw_econv_thr, ts_vdw_isolated, xdm_a1, xdm_a2 + + + +Type of Van der Waals correction. Allowed values: + + +Semiempirical Grimme's DFT-D2. +Optional variables: london_s6, london_rcut, london_c6, london_rvdw, +S. Grimme, J. Comp. Chem. 27, 1787 (2006), +V. Barone et al., J. Comp. Chem. 30, 934 (2009). + + +Tkatchenko-Scheffler dispersion corrections with first-principle derived +C6 coefficients (implemented in CP only). +Optional variables: ts_vdw_econv_thr, ts_vdw_isolated +See A. Tkatchenko and M. Scheffler, PRL 102, 073005 (2009). + + +Exchange-hole dipole-moment model. Optional variables: xdm_a1, xdm_a2 +A. D. Becke and E. R. Johnson, J. Chem. Phys. 127, 154108 (2007) +A. Otero de la Roza, E. R. Johnson, J. Chem. Phys. 136, 174109 (2012) + + Note that non-local functionals (eg vdw-DF) are NOT specified here but in input_dft + + + + + .FALSE. + + +OBSOLESCENT, same as vdw_corr='DFT-D' + + + + 0.75 + + +global scaling parameter for DFT-D. Default is good for PBE. + + + + standard Grimme-D2 values + + +atomic C6 coefficient of each atom type + +( if not specified default values from S. Grimme, J. Comp. Chem. 27, 1787 (2006) are used; + see file Modules/mm_dispersion.f90 ) + + + + standard Grimme-D2 values + + +atomic vdw radii of each atom type + +( if not specified default values from S. Grimme, J. Comp. Chem. 27, 1787 (2006) are used; + see file Modules/mm_dispersion.f90 ) + + + + 200 + + +cutoff radius (a.u.) for dispersion interactions + + + + 1.D-6 + + +Optional: controls the convergence of the vdW energy (and forces). The default value +is a safe choice, likely too safe, but you do not gain much in increasing it + + + + .FALSE. + + +Optional: set it to .TRUE. when computing the Tkatchenko-Scheffler vdW energy +for an isolated (non-periodic) system. + + + + .FALSE. + + +OBSOLESCENT, same as vdw_corr='xdm' + + + + 0.6836 + + +Damping function parameter a1 (adimensional). This value should change +with the exchange-correlation functional. The default corresponds to +PW86PBE. +For other functionals, see: + http://schooner.chem.dal.ca/wiki/XDM + A. Otero de la Roza, E. R. Johnson, J. Chem. Phys. 138, 204109 (2013) + + + + 1.5045 + + +Damping function parameter a2 (angstrom). This value should change +with the exchange-correlation functional. The default corresponds to +PW86PBE. +For other functionals, see: + http://schooner.chem.dal.ca/wiki/XDM + A. Otero de la Roza, E. R. Johnson, J. Chem. Phys. 138, 204109 (2013) + + + + 0 + + +The number of the space group of the crystal, as given +in the International Tables of Crystallography A (ITA). +This allows to give in input only the inequivalent atomic +positions. The positions of all the symmetry equivalent atoms +are calculated by the code. Used only when the atomic positions +are of type crystal_sg. + + + + .FALSE. + + +Used only for monoclinic lattices. If .TRUE. the b +unique ibrav (-12 or -13) are used, and symmetry +equivalent positions are chosen assuming that the +two fold axis or the mirror normal is parallel to the +b axis. If .FALSE. it is parallel to the c axis. + + + + 1 + + +Used only for space groups that in the ITA allow +the use of two different origins. origin_choice=1, +means the first origin, while origin_choice=2 is the +second origin. + + + + .TRUE. + + +Used only for rhombohedral space groups. +When .TRUE. the coordinates of the inequivalent atoms are +given with respect to the rhombohedral axes, when .FALSE. +the coordinates of the inequivalent atoms are given with +respect to the hexagonal axes. They are converted internally +to the rhombohedral axes and ibrav=5 is used in both cases. + + + + + + 0.5 + + +used only if monopole = .TRUE. +Specifies the position of the charged plate which represents +the counter charge in doped systems (tot_charge .ne. 0). +In units of the unit cell length in z direction, zmon in ]0,1[ +Details of the monopole potential can be found in +T. Brumme, M. Calandra, F. Mauri; PRB 89, 245406 (2014). + + + + .FALSE. + + +used only if monopole = .TRUE. +Allows the relaxation of the system towards the charged plate. +Use carefully and utilize either a layer of fixed atoms or a +potential barrier (block=.TRUE.) to avoid the atoms moving to +the position of the plate or the dipole of the dipole +correction (dipfield=.TRUE.). + + + + .FALSE. + + +used only if monopole = .TRUE. +Adds a potential barrier to the total potential seen by the +electrons to mimic a dielectric in field effect configuration +and/or to avoid electrons spilling into the vacuum region for +electron doping. Potential barrier is from block_1 to block_2 and +has a height of block_height. +If dipfield = .TRUE. then eopreg is used for a smooth increase and +decrease of the potential barrier. + + + + 0.45 + + +used only if monopole = .TRUE. and block = .TRUE. +lower beginning of the potential barrier, in units of the +unit cell size along z, block_1 in ]0,1[ + + + + 0.55 + + +used only if monopole = .TRUE. and block = .TRUE. +upper beginning of the potential barrier, in units of the +unit cell size along z, block_2 in ]0,1[ + + + + 0.1 + + +used only if monopole = .TRUE. and block = .TRUE. +Height of the potential barrier in Rydberg. + + + + + + + 100 + + +maximum number of iterations in a scf step + + + + .TRUE. + + +If .false. do not stop molecular dynamics or ionic relaxation +when electron_maxstep is reached. Use with care. + + + + 1.D-6 + + +Convergence threshold for selfconsistency: + estimated energy error < conv_thr +(note that conv_thr is extensive, like the total energy). + +For non-self-consistent calculations, conv_thr is used +to set the default value of the threshold (ethr) for +iterative diagonalizazion: see diago_thr_init + + + + .FALSE + + +If .TRUE. this turns on the use of an adaptive conv_thr for +the inner scf loops when using EXX. + + + + 1.D-3 + + +When adaptive_thr = .TRUE. this is the convergence threshold +used for the first scf cycle. + + + + 1.D-1 + + +When adaptive_thr = .TRUE. the convergence threshold for +each scf cycle is given by: +max( conv_thr, conv_thr_multi * dexx ) + + + + 'plain' + + + Available options are: + + charge density Broyden mixing + + +as above, with simple Thomas-Fermi screening +(for highly homogeneous systems) + + +as above, with local-density-dependent TF screening +(for highly inhomogeneous systems) + + + + + 0.7D0 + + +mixing factor for self-consistency + + + + 8 + + +number of iterations used in mixing scheme. +If you are tight with memory, you may reduce it to 4 or so. + + + + 0 + + +For DFT+U : number of iterations with fixed ns ( ns is the +atomic density appearing in the Hubbard term ). + + + + 'david' + + + Available options are: + + +Davidson iterative diagonalization with overlap matrix +(default). Fast, may in some rare cases fail. + + +Conjugate-gradient-like band-by-band diagonalization. +Typically slower than 'david' but it uses less memory +and is more robust (it seldom fails). + + +OBSOLETE, use -ndiag 1 instead. +The subspace diagonalization in Davidson is performed +by a fully distributed-memory parallel algorithm on +4 or more processors, by default. The allocated memory +scales down with the number of procs. Procs involved +in diagonalization can be changed with command-line +option -ndiag N. On multicore CPUs it is often +convenient to let just one core per CPU to work +on linear algebra. + + + + + 0 + + OBSOLETE: use command-line option "-ndiag XX" instead + + + + +Convergence threshold (ethr) for iterative diagonalization +(the check is on eigenvalue convergence). + +For scf calculations: default is 1.D-2 if starting from a +superposition of atomic orbitals; 1.D-5 if starting from a +charge density. During self consistency the threshold +is automatically reduced (but never below 1.D-13) when +approaching convergence. + +For non-scf calculations: default is (conv_thr/N elec)/10. + + + + +For conjugate gradient diagonalization: max number of iterations + + + + 4 + + +For Davidson diagonalization: dimension of workspace +(number of wavefunction packets, at least 2 needed). +A larger value may yield a somewhat faster algorithm +but uses more memory. The opposite holds for smaller values. +Try diago_david_ndim=2 if you are tight on memory or if +your job is large: the speed penalty is often negligible + + + + .FALSE. + + +If .TRUE. all the empty states are diagonalized at the same level +of accuracy of the occupied ones. Otherwise the empty states are +diagonalized using a larger threshold (this should not affect +total energy, forces, and other ground-state properties). + + + + 0.D0 + + +Amplitude of the finite electric field (in Ry a.u.; +1 a.u. = 36.3609*10^10 V/m). Used only if lelfield==.TRUE. +and if k-points (K_POINTS card) are not automatic. + + + + (0.D0, 0.D0, 0.D0) + + +Finite electric field (in Ry a.u.=36.3609*10^10 V/m) in +cartesian axis. Used only if lelfield==.TRUE. and if +k-points (K_POINTS card) are automatic. + + + + 'none' + + + Available options are: + + +set the zero of the electronic polarization (with lelfield==.true..) +to the result of a previous calculation + + +write on disk data on electronic polarization to be read in another +calculation + + +none of the above points + + + + + + Available options are: + + +starting potential from atomic charge superposition +(default for scf, *relax, *md) + + +start from existing "charge-density.xml" file in the +directory specified by variables prefix and outdir +For nscf and bands calculation this is the default +and the only sensible possibility. + + + + + 'atomic+random' + + + Available options are: + + +Start from superposition of atomic orbitals. +If not enough atomic orbitals are available, +fill with random numbers the remaining wfcs +The scf typically starts better with this option, +but in some high-symmetry cases one can "loose" +valence states, ending up in the wrong ground state. + + +As above, plus a superimposed "randomization" +of atomic orbitals. Prevents the "loss" of states +mentioned above. + + +Start from random wfcs. Slower start of scf but safe. +It may also reduce memory usage in conjunction with +diagonalization='cg'. + + +Start from an existing wavefunction file in the +directory specified by variables prefix and outdir. + + + + + .FALSE. + + +If .true., use the real-space algorithm for augmentation +charges in ultrasoft pseudopotentials. +Must faster execution of ultrasoft-related calculations, +but numerically less accurate than the default algorithm. +Use with care and after testing! + + + + + + + + +Specify the type of ionic dynamics. + +For different type of calculation different possibilities are +allowed and different default values apply: + +CASE ( calculation == 'relax' ) + + +(default) use BFGS quasi-newton algorithm, +based on the trust radius procedure, +for structural relaxation + + +use damped (quick-min Verlet) +dynamics for structural relaxation +Can be used for constrained +optimisation: see CONSTRAINTS card + + +CASE ( calculation == 'md' ) + + +(default) use Verlet algorithm to integrate +Newton's equation. For constrained +dynamics, see CONSTRAINTS card + + +ion dynamics is over-damped Langevin + + +over-damped Langevin with Smart Monte Carlo: +see R.J. Rossky, JCP, 69, 4628(1978) + + +CASE ( calculation == 'vc-relax' ) + + +(default) use BFGS quasi-newton algorithm; +cell_dynamics must be 'bfgs' too + + +use damped (Beeman) dynamics for +structural relaxation + + +CASE ( calculation == 'vc-md' ) + + +(default) use Beeman algorithm to integrate +Newton's equation + + + + + 'default' + + + Available options are: + + +if restarting, use atomic positions read from the +restart file; in all other cases, use atomic +positions from standard input. + + +restart the simulation with atomic positions read +from standard input, even if restarting. + + + + + 'atomic' + + + +Used to extrapolate the potential from preceding ionic steps. + + no extrapolation + + +extrapolate the potential as if it was a sum of +atomic-like orbitals + + +extrapolate the potential with first-order +formula + + +as above, with second order formula + + +Note: 'first_order' and 'second-order' extrapolation make sense +only for molecular dynamics calculations + + + + + 'none' + + + +Used to extrapolate the wavefunctions from preceding ionic steps. + + no extrapolation + + +extrapolate the wave-functions with first-order formula. + + +as above, with second order formula. + + +Note: 'first_order' and 'second-order' extrapolation make sense +only for molecular dynamics calculations + + + + + .FALSE. + + +This keyword is useful when simulating the dynamics and/or the +thermodynamics of an isolated system. If set to true the total +torque of the internal forces is set to zero by adding new forces +that compensate the spurious interaction with the periodic +images. This allows for the use of smaller supercells. + +BEWARE: since the potential energy is no longer consistent with +the forces (it still contains the spurious interaction with the +repeated images), the total energy is not conserved anymore. +However the dynamical and thermodynamical properties should be +in closer agreement with those of an isolated system. +Also the final energy of a structural relaxation will be higher, +but the relaxation itself should be faster. + + + + + + 'not_controlled' + + + Available options are: + + +control ionic temperature via velocity rescaling +(first method) see parameters tempw, tolp, and +nraise (for VC-MD only). This rescaling method +is the only one currently implemented in VC-MD + + +control ionic temperature via velocity rescaling +(second method) see parameters tempw and nraise + + +control ionic temperature via velocity rescaling +(third method) see parameter delta_t + + +reduce ionic temperature every nraise steps +by the (negative) value delta_t + + +control ionic temperature using "soft" velocity +rescaling - see parameters tempw and nraise + + +control ionic temperature using Andersen thermostat +see parameters tempw and nraise + + +initialize ion velocities to temperature tempw +and leave uncontrolled further on + + +(default) ionic temperature is not controlled + + + + + 300.D0 + + +Starting temperature (Kelvin) in MD runs +target temperature for most thermostats. + + + + 100.D0 + + +Tolerance for velocity rescaling. Velocities are rescaled if +the run-averaged and target temperature differ more than tolp. + + + + 1.D0 + + +if ion_temperature == 'rescale-T' : + at each step the instantaneous temperature is multiplied + by delta_t; this is done rescaling all the velocities. + +if ion_temperature == 'reduce-T' : + every 'nraise' steps the instantaneous temperature is + reduced by -delta_t (i.e. delta_t < 0 is added to T) + +The instantaneous temperature is calculated at the end of +every ionic move and BEFORE rescaling. This is the temperature +reported in the main output. + +For delta_t < 0, the actual average rate of heating or cooling +should be roughly C*delta_t/(nraise*dt) (C=1 for an +ideal gas, C=0.5 for a harmonic solid, theorem of energy +equipartition between all quadratic degrees of freedom). + + + + 1 + + +if ion_temperature == 'reduce-T' : + every nraise steps the instantaneous temperature is + reduced by -delta_t (i.e. delta_t is added to the temperature) + +if ion_temperature == 'rescale-v' : + every nraise steps the average temperature, computed from + the last nraise steps, is rescaled to tempw + +if ion_temperature == 'rescaling' and calculation == 'vc-md' : + every nraise steps the instantaneous temperature + is rescaled to tempw + +if ion_temperature == 'berendsen' : + the "rise time" parameter is given in units of the time step: + tau = nraise*dt, so dt/tau = 1/nraise + +if ion_temperature == 'andersen' : + the "collision frequency" parameter is given as nu=1/tau + defined above, so nu*dt = 1/nraise + + + + .FALSE. + + +This keyword applies only in the case of molecular dynamics or +damped dynamics. If true the ions are refolded at each step into +the supercell. + + + + + + + 100.D0 + + +Max reduction factor for conv_thr during structural optimization +conv_thr is automatically reduced when the relaxation +approaches convergence so that forces are still accurate, +but conv_thr will not be reduced to less that conv_thr / upscale. + + + + 1 + + +Number of old forces and displacements vectors used in the +PULAY mixing of the residual vectors obtained on the basis +of the inverse hessian matrix given by the BFGS algorithm. +When bfgs_ndim = 1, the standard quasi-Newton BFGS method is +used. +(bfgs only) + + + + 0.8D0 + + +Maximum ionic displacement in the structural relaxation. +(bfgs only) + + + + 1.D-3 + + +Minimum ionic displacement in the structural relaxation +BFGS is reset when trust_radius < trust_radius_min. +(bfgs only) + + + + 0.5D0 + + +Initial ionic displacement in the structural relaxation. +(bfgs only) + + + + 0.01D0 + + w_2 + + + + 0.5D0 + + +Parameters used in line search based on the Wolfe conditions. +(bfgs only) + + + + + + + + + +Specify the type of dynamics for the cell. +For different type of calculation different possibilities +are allowed and different default values apply: + +CASE ( calculation == 'vc-relax' ) + + no dynamics + + steepest descent ( not implemented ) + + +damped (Beeman) dynamics of the Parrinello-Rahman extended lagrangian + + +damped (Beeman) dynamics of the new Wentzcovitch extended lagrangian + + +BFGS quasi-newton algorithm (default) +ion_dynamics must be 'bfgs' too + + +CASE ( calculation == 'vc-md' ) + + no dynamics + + +(Beeman) molecular dynamics of the Parrinello-Rahman extended lagrangian + + +(Beeman) molecular dynamics of the new Wentzcovitch extended lagrangian + + + + + 0.D0 + + +Target pressure [KBar] in a variable-cell md or relaxation run. + + + + +0.75*Tot_Mass/pi**2 for Parrinello-Rahman MD; +0.75*Tot_Mass/pi**2/Omega**(2/3) for Wentzcovitch MD + + +Fictitious cell mass [amu] for variable-cell simulations +(both 'vc-md' and 'vc-relax') + + + + 1.2D0 + + +Used in the construction of the pseudopotential tables. +It should exceed the maximum linear contraction of the +cell during a simulation. + + + + 0.5D0 Kbar + + +Convergence threshold on the pressure for variable cell +relaxation ('vc-relax' : note that the other convergence + thresholds for ionic relaxation apply as well). + + + + 'all' + + + +Select which of the cell parameters should be moved: + + all axis and angles are moved + + only the x component of axis 1 (v1_x) is moved + + only the y component of axis 2 (v2_y) is moved + + only the z component of axis 3 (v3_z) is moved + + only v1_x and v2_y are moved + + only v1_x and v3_z are moved + + only v2_y and v3_z are moved + + only v1_x, v2_y, v3_z are moved + + all axis and angles, keeping the volume fixed + + the volume changes, keeping all angles fixed (i.e. only celldm(1) changes) + + only x and y components are allowed to change + + as above, keeping the area in xy plane fixed + + +BEWARE: if axis are not orthogonal, some of these options do not + work (symmetry is broken). If you are not happy with them, + edit subroutine init_dofree in file Modules/cell_base.f90 + + + + + + + + + + +label of the atom. Acceptable syntax: +chemical symbol X (1 or 2 characters, case-insensitive) +or chemical symbol plus a number or a letter, as in +"Xn" (e.g. Fe1) or "X_*" or "X-*" (e.g. C1, C_h; +max total length cannot exceed 3 characters) + + + + +mass of the atomic species [amu: mass of C = 12] +Used only when performing Molecular Dynamics run +or structural optimization runs using Damped MD. +Not actually used in all other cases (but stored +in data files, so phonon calculations will use +these values unless other values are provided) + + + + +File containing PP for this species. + +The pseudopotential file is assumed to be in the new UPF format. +If it doesn't work, the pseudopotential format is determined by +the file name: + +*.vdb or *.van Vanderbilt US pseudopotential code +*.RRKJ3 Andrea Dal Corso's code (old format) +none of the above old PWscf norm-conserving format + + + +
+ + + + + alat | bohr | angstrom | crystal | crystal_sg + + (DEPRECATED) alat + + + +Units for ATOMIC_POSITIONS: + + +atomic positions are in cartesian coordinates, in +units of the lattice parameter (either celldm(1) +or A). If no option is specified, 'alat' is assumed; +not specifying units is DEPRECATED and will no +longer be allowed in the future + + +atomic positions are in cartesian coordinate, +in atomic units (i.e. Bohr radii) + + +atomic positions are in cartesian coordinates, in Angstrom + + +atomic positions are in crystal coordinates, i.e. +in relative coordinates of the primitive lattice +vectors as defined either in card CELL_PARAMETERS +or via the ibrav + celldm / a,b,c... variables + + +atomic positions are in crystal coordinates, i.e. +in relative coordinates of the primitive lattice. +This option differs from the previous one because +in this case only the symmetry inequivalent atoms +are given. The variable space_group must indicate +the space group number used to find the symmetry +equivalent atoms. The other variables that control +this option are uniqueb, origin_choice, and +rhombohedral. + + + + + + +Specified atomic positions will be IGNORED and those from the +previous scf calculation will be used instead !!! + + + + + + + + label of the atom as specified in ATOMIC_SPECIES + + + + +atomic positions + +NOTE: each atomic coordinate can also be specified as a simple algebraic expression. + To be interpreted correctly expression must NOT contain any blank + space and must NOT start with a "+" sign. The available expressions are: + + + (plus), - (minus), / (division), * (multiplication), ^ (power) + + All numerical constants included are considered as double-precision numbers; + i.e. 1/2 is 0.5, not zero. Other functions, such as sin, sqrt or exp are + not available, although sqrt can be replaced with ^(1/2). + + Example: + C 1/3 1/2*3^(-1/2) 0 + + is equivalent to + + C 0.333333 0.288675 0.000000 + + Please note that this feature is NOT supported by XCrysDen (which will + display a wrong structure, or nothing at all). + + When atomic positions are of type crystal_sg coordinates can be given + in the following four forms (Wyckoff positions): + C 1a + C 8g x + C 24m x y + C 48n x y z + The first form must be used when the Wyckoff letter determines uniquely + all three coordinates, forms 2,3,4 when the Wyckoff letter and 1,2,3 + coordinates respectively are needed. + + The forms: + C 8g x x x + C 24m x x y + are not allowed, but + C x x x + C x x y + C x y z + are correct. + + + + + + + + + + + +component i of the force for this atom is multiplied by if_pos(i), +which must be either 0 or 1. Used to keep selected atoms and/or +selected components fixed in MD dynamics or +structural optimization run. + +With crystal_sg atomic coordinates the constraints are copied in all equivalent +atoms. + + 1 + + + + + + + + + + +
+ + + + + + + tpiba | automatic | crystal | gamma | tpiba_b | crystal_b | tpiba_c | crystal_c + + tbipa + + + +K_POINTS options are: + + +read k-points in cartesian coordinates, +in units of 2 pi/a (default) + + +automatically generated uniform grid of k-points, i.e, +generates ( nk1, nk2, nk3 ) grid with ( sk1, sk2, sk3 ) offset. +nk1, nk2, nk3 as in Monkhorst-Pack grids +k1, k2, k3 must be 0 ( no offset ) or 1 ( grid displaced +by half a grid step in the corresponding direction ) +BEWARE: only grids having the full symmetry of the crystal + work with tetrahedra. Some grids with offset may not work. + + +read k-points in crystal coordinates, i.e. in relative +coordinates of the reciprocal lattice vectors + + +use k = 0 (no need to list k-point specifications after card) +In this case wavefunctions can be chosen as real, +and specialized subroutines optimized for calculations +at the gamma point are used (memory and cpu requirements +are reduced by approximately one half). + + +Used for band-structure plots. +k-points are in units of 2 pi/a. +nks points specify nks-1 lines in reciprocal space. +Every couple of points identifies the initial and +final point of a line. pw.x generates N intermediate +points of the line where N is the weight of the first point. + + +As tpiba_b, but k-points are in crystal coordinates. + + +Used for band-structure contour plots. +k-points are in units of 2 pi/a. nks must be 3. +3 k-points k_0, k_1, and k_2 specify a rectangle +in reciprocal space of vertices k_0, k_1, k_2, +k_1 + k_2 - k_0: k_0 + \alpha (k_1-k_0)+ +\beta (k_2-k_0) with 0 <\alpha,\beta < 1. +The code produces a uniform mesh n1 x n2 +k points in this rectangle. n1 and n2 are +the weights of k_1 and k_2. The weight of k_0 +is not used. + + +As tpiba_c, but k-points are in crystal coordinates. + + + + + + + + + Number of supplied special k-points. + + + + + + + + + + + + + + + +Special k-points (xk_x/y/z) in the irreducible Brillouin Zone +(IBZ) of the lattice (with all symmetries) and weights (wk) +See the literature for lists of special points and +the corresponding weights. + +If the symmetry is lower than the full symmetry +of the lattice, additional points with appropriate +weights are generated. Notice that such procedure +assumes that ONLY k-points in the IBZ are provided in input + +In a non-scf calculation, weights do not affect the results. +If you just need eigenvalues and eigenvectors (for instance, +for a band-structure plot), weights can be set to any value +(for instance all equal to 1). + + + +
+ + + + + + + + + + + + + +These parameters specify the k-point grid +(nk1 x nk2 x nk3) as in Monkhorst-Pack grids. + + + + + + + + + + +The grid offsets; sk1, sk2, sk3 must be +0 ( no offset ) or 1 ( grid displaced by +half a grid step in the corresponding direction ). + + + + + + + + + + + + + + alat | bohr | angstrom + + +Unit for lattice vectors; options are: + +'bohr' / 'angstrom': + lattice vectors in bohr-radii / angstrom. + In this case the lattice parameter alat = sqrt(v1*v1). + +'alat' / nothing specified: + lattice vectors in units of the lattice parameter (either + celldm(1) or A). Not specifying units is DEPRECATED + and will not be allowed in the future. + +If neither unit nor lattice parameter are specified, +'bohr' is assumed - DEPRECATED, will no longer be allowed + + + + + + + + +Crystal lattice vectors (in cartesian axis): + v1(1) v1(2) v1(3) ... 1st lattice vector + v2(1) v2(2) v2(3) ... 2nd lattice vector + v3(1) v3(2) v3(3) ... 3rd lattice vector + + + + + + + + + +
+ + + + + +When this card is present the SHAKE algorithm is automatically used. + + + + + Number of constraints. + + + + + Tolerance for keeping the constraints satisfied. + + + + + + + + + +Type of constraint : + + +constraint on global coordination-number, i.e. the +average number of atoms of type B surrounding the +atoms of type A. The coordination is defined by +using a Fermi-Dirac. +(four indexes must be specified). + + +constraint on local coordination-number, i.e. the +average number of atoms of type A surrounding a +specific atom. The coordination is defined by +using a Fermi-Dirac. +(four indexes must be specified). + + +constraint on interatomic distance +(two atom indexes must be specified). + + +constraint on planar angle +(three atom indexes must be specified). + + +constraint on torsional angle +(four atom indexes must be specified). + + +constraint on the projection onto a given direction +of the vector defined by the position of one atom +minus the center of mass of the others. +G. Roma, J.P. Crocombette: J. Nucl. Mater. 403, 32 (2010) + + + + + + + + + + + + + + + +These variables have different meanings for different constraint types: + +'type_coord' : + constr(1) is the first index of the atomic type involved + constr(2) is the second index of the atomic type involved + constr(3) is the cut-off radius for estimating the coordination + constr(4) is a smoothing parameter + +'atom_coord' : + constr(1) is the atom index of the atom with constrained coordination + constr(2) is the index of the atomic type involved in the coordination + constr(3) is the cut-off radius for estimating the coordination + constr(4) is a smoothing parameter + +'distance' : + atoms indices object of the constraint, as they appear in + the ATOMIC_POSITIONS card + +'planar_angle', 'torsional_angle' : + atoms indices object of the constraint, as they appear in the + ATOMIC_POSITIONS card (beware the order) + +'bennett_proj' : + constr(1) is the index of the atom whose position is constrained. + constr(2:4) are the three coordinates of the vector that specifies + the constraint direction. + + + + + +Target for the constrain ( angles are specified in degrees ). +This variable is optional. + + + + +
+ + + + + + + + + +Occupations of individual states (MAX 10 PER ROW). +For spin-polarized calculations, these are majority spin states. + + + + + +Occupations of minority spin states (MAX 10 PER ROW) +To be specified only for spin-polarized calculations. + + + + +
+ + + + + +BEWARE: if the sum of external forces is not zero, the center of mass of + the system will move + + + + + + label of the atom as specified in ATOMIC_SPECIES + + + + +external force on atom X (cartesian components, Ry/a.u. units) + + + + + + + + + +
+ + + diff --git a/aiida_quantumespresso/calculations/helpers/INPUT_PW-6.1.xml b/aiida_quantumespresso/calculations/helpers/INPUT_PW-6.1.xml new file mode 100644 index 000000000..3acff49d7 --- /dev/null +++ b/aiida_quantumespresso/calculations/helpers/INPUT_PW-6.1.xml @@ -0,0 +1,2964 @@ + + + + + + + + +Input data format: { } = optional, [ ] = it depends, | = or + +All quantities whose dimensions are not explicitly specified are in +RYDBERG ATOMIC UNITS. Charge is "number" charge (i.e. not multiplied +by e); potentials are in energy units (i.e. they are multiplied by e). + +BEWARE: TABS, DOS <CR><LF> CHARACTERS ARE POTENTIAL SOURCES OF TROUBLE + +Comment lines in namelists can be introduced by a "!", exactly as in +fortran code. Comments lines in cards can be introduced by +either a "!" or a "#" character in the first position of a line. +Do not start any line in cards with a "/" character. + + +Structure of the input data: +=============================================================================== + +&CONTROL + ... +/ + +&SYSTEM + ... +/ + +&ELECTRONS + ... +/ + +[ &IONS + ... + / ] + +[ &CELL + ... + / ] + +ATOMIC_SPECIES + X Mass_X PseudoPot_X + Y Mass_Y PseudoPot_Y + Z Mass_Z PseudoPot_Z + +ATOMIC_POSITIONS { alat | bohr | crystal | angstrom | crystal_sg } + X 0.0 0.0 0.0 {if_pos(1) if_pos(2) if_pos(3)} + Y 0.5 0.0 0.0 + Z O.0 0.2 0.2 + +K_POINTS { tpiba | automatic | crystal | gamma | tpiba_b | crystal_b | tpiba_c | crystal_c } +if (gamma) + nothing to read +if (automatic) + nk1, nk2, nk3, k1, k2, k3 +if (not automatic) + nks + xk_x, xk_y, xk_z, wk + +[ CELL_PARAMETERS { alat | bohr | angstrom } + v1(1) v1(2) v1(3) + v2(1) v2(2) v2(3) + v3(1) v3(2) v3(3) ] + +[ OCCUPATIONS + f_inp1(1) f_inp1(2) f_inp1(3) ... f_inp1(10) + f_inp1(11) f_inp1(12) ... f_inp1(nbnd) + [ f_inp2(1) f_inp2(2) f_inp2(3) ... f_inp2(10) + f_inp2(11) f_inp2(12) ... f_inp2(nbnd) ] ] + +[ CONSTRAINTS + nconstr { constr_tol } + constr_type(.) constr(1,.) constr(2,.) [ constr(3,.) constr(4,.) ] { constr_target(.) } ] + +[ ATOMIC_FORCES + label_1 Fx(1) Fy(1) Fz(1) + ..... + label_n Fx(n) Fy(n) Fz(n) ] + + + + 'scf' + + + +A string describing the task to be performed. Options are: + + + + + + + + + + + + + + + + +(vc = variable-cell). + + + + + ' ' + + +reprinted on output. + + + + 'low' + + + +Currently two verbosity levels are implemented: + + + + + + +'debug' and 'medium' have the same effect as 'high'; +'default' and 'minimal' as 'low' + + + + + 'from_scratch' + + + Available options are: + + +From scratch. This is the normal way to perform a PWscf calculation + + +From previous interrupted run. Use this switch only if you want to +continue an interrupted calculation, not to start a new one, or to +perform non-scf calculations. Works only if the calculation was +cleanly stopped using variable max_seconds, or by user request +with an "exit file" (i.e.: create a file "prefix".EXIT, in directory +"outdir"; see variables prefix, outdir). Overrides startingwfc +and startingpot. + + + + + .FALSE. + + +This flag controls the way wavefunctions are stored to disk : + +.TRUE. collect wavefunctions from all processors, store them + into the output data directory "outdir"/"prefix".save, + ... + + .FALSE. do not collect wavefunctions, leave them in temporary + local files (one per processor). The resulting format + ... + +Note that this flag has no effect on reading, only on writing. + + + + +number of molecular-dynamics or structural optimization steps +performed in this run + + +1 if calculation == 'scf', 'nscf', 'bands'; +50 for the other cases + + + + write only at convergence + + +band energies are written every iprint iterations + + + + .false. + + +calculate stress. It is set to .TRUE. automatically if +calculation == 'vc-md' or 'vc-relax' + + + + +calculate forces. It is set to .TRUE. automatically if +calculation == 'relax','md','vc-md' + + + + 20.D0 + + +time step for molecular dynamics, in Rydberg atomic units +(1 a.u.=4.8378 * 10^-17 s : beware, the CP code uses + Hartree atomic units, half that much!!!) + + + + +value of the ESPRESSO_TMPDIR environment variable if set; +current directory ('./') otherwise + + +input, temporary, output files are found in this directory, +see also wfcdir + + + + same as outdir + + +This directory specifies where to store files generated by +each processor (*.wfc{N}, *.igk{N}, etc.). Useful for +machines without a parallel file system: set wfcdir to +a local file system, while outdir should be a parallel +or networkfile system, visible to all processors. Beware: +in order to restart from interrupted runs, or to perform +further calculations using the produced data files, you +may need to copy files to outdir. Works only for pw.x. + + + + 'pwscf' + + +prepended to input/output filenames: +prefix.wfc, prefix.rho, etc. + + + + .true. + + +If .false. a subdirectory for each k_point is not opened +in the "prefix".save directory; Kohn-Sham eigenvalues are +stored instead in a single file for all k-points. Currently +doesn't work together with wf_collect + + + + 1.D+7, or 150 days, i.e. no time limit + + +Jobs stops after max_seconds CPU time. Use this option +in conjunction with option restart_mode if you need to +split a job too long to complete into shorter jobs that +fit into your batch queues. + + + + 1.0D-4 + + +Convergence threshold on total energy (a.u) for ionic +minimization: the convergence criterion is satisfied +when the total energy changes less than etot_conv_thr +between two consecutive scf steps. Note that etot_conv_thr +is extensive, like the total energy. +See also forc_conv_thr - both criteria must be satisfied + + + + 1.0D-3 + + +Convergence threshold on forces (a.u) for ionic minimization: +the convergence criterion is satisfied when all components of +all forces are smaller than forc_conv_thr. +See also etot_conv_thr - both criteria must be satisfied + + + + see below + + + +Specifies the amount of disk I/O activity: + + +save all data to disk at each SCF step + + +save wavefunctions at each SCF step unless +there is a single k-point per process (in which +case the behavior is the same as 'low') + + +store wfc in memory, save only at the end + + +do not save anything, not even at the end +('scf', 'nscf', 'bands' calculations; some data +may be written anyway for other calculations) + + +Default is 'low' for the scf case, 'medium' otherwise. +Note that the needed RAM increases as disk I/O decreases! +It is no longer needed to specify 'high' in order to be able +to restart from an interrupted calculation (see restart_mode) +but you cannot restart in disk_io=='none' + + + + + +value of the $ESPRESSO_PSEUDO environment variable if set; +'$HOME/espresso/pseudo/' otherwise + + +directory containing pseudopotential files + + + + .FALSE. + + +If .TRUE. a saw-like potential simulating an electric field +is added to the bare ionic potential. See variables edir, +eamp, emaxpos, eopreg for the form and size of +the added potential. + + + + .FALSE. + + +If .TRUE. and tefield==.TRUE. a dipole correction is also +added to the bare ionic potential - implements the recipe +of L. Bengtsson, PRB 59, 12301 (1999). See variables edir, +emaxpos, eopreg for the form of the correction. Must +be used ONLY in a slab geometry, for surface calculations, +with the discontinuity FALLING IN THE EMPTY SPACE. + + + + .FALSE. + + +If .TRUE. a homogeneous finite electric field described +through the modern theory of the polarization is applied. +This is different from tefield == .true. ! + + + + 1 + + +In the case of a finite electric field ( lelfield == .TRUE. ) +it defines the number of iterations for converging the +wavefunctions in the electric field Hamiltonian, for each +external iteration on the charge density + + + + .FALSE. + + +If .TRUE. perform orbital magnetization calculation. +If finite electric field is applied (lelfield==.true.) only Kubo terms are computed +[for details see New J. Phys. 12, 053032 (2010), doi:10.1088/1367-2630/12/5/053032]. + +The type of calculation is 'nscf' and should be performed on an automatically +generated uniform grid of k points. + +Works ONLY with norm-conserving pseudopotentials. + + + + .FALSE. + + +If .TRUE. perform a Berry phase calculation. +See the header of PW/src/bp_c_phase.f90 for documentation. + + + + +For Berry phase calculation: direction of the k-point +strings in reciprocal space. Allowed values: 1, 2, 3 +1=first, 2=second, 3=third reciprocal lattice vector +For calculations with finite electric fields +(lelfield==.true.) "gdir" is the direction of the field. + + + + +For Berry phase calculation: number of k-points to be +calculated along each symmetry-reduced string. +The same for calculation with finite electric fields +(lelfield==.true.). + + + + fcp_mu + + .FALSE. + + +If .TRUE. perform a constant bias potential (constant-mu) calculation +for a static system with ESM method. See the header of PW/src/fcp.f90 +for documentation. + +NB: +- The total energy displayed in 'prefix.out' includes the potentiostat + contribution (-mu*N). +- calculation must be 'relax'. +- assume_isolated = 'esm' and esm_bc = 'bc2' or 'bc3' must be set + in SYSTEM namelist. + + + + .FALSE. + + zmon, realxz, block, block_1, block_2, block_height + + +In the case of charged cells (tot_charge .ne. 0) setting monopole = .TRUE. +represents the counter charge (i.e. -tot_charge) not by a homogenous +background charge but with a charged plate, which is placed at zmon +(see below). Details of the monopole potential can be found in +T. Brumme, M. Calandra, F. Mauri; PRB 89, 245406 (2014). +Note, that in systems which are not symmetric with respect to the plate, +one needs to enable the dipole correction! (dipfield=.true.). +Currently, symmetry can be used with monopole=.true. but carefully check +that no symmetry is included which maps z to -z even if in principle one +could still use them for symmetric systems (i.e. no dipole correction). +For nosym=.false. verbosity is set to 'high'. + + + + + + REQUIRED + + + Bravais-lattice index. If ibrav /= 0, specify EITHER + [ celldm(1)-celldm(6) ] OR [ A, B, C, cosAB, cosAC, cosBC ] + but NOT both. The lattice parameter "alat" is set to + alat = celldm(1) (in a.u.) or alat = A (in Angstrom); + see below for the other parameters. + For ibrav=0 specify the lattice vectors in CELL_PARAMETERS, + optionally the lattice parameter alat = celldm(1) (in a.u.) + or = A (in Angstrom), or else it is taken from CELL_PARAMETERS + +ibrav structure celldm(2)-celldm(6) + or: b,c,cosab,cosac,cosbc + 0 free + crystal axis provided in input: see card CELL_PARAMETERS + + 1 cubic P (sc) + v1 = a(1,0,0), v2 = a(0,1,0), v3 = a(0,0,1) + + 2 cubic F (fcc) + v1 = (a/2)(-1,0,1), v2 = (a/2)(0,1,1), v3 = (a/2)(-1,1,0) + + 3 cubic I (bcc) + v1 = (a/2)(1,1,1), v2 = (a/2)(-1,1,1), v3 = (a/2)(-1,-1,1) + + 4 Hexagonal and Trigonal P celldm(3)=c/a + v1 = a(1,0,0), v2 = a(-1/2,sqrt(3)/2,0), v3 = a(0,0,c/a) + + 5 Trigonal R, 3fold axis c celldm(4)=cos(alpha) + The crystallographic vectors form a three-fold star around + the z-axis, the primitive cell is a simple rhombohedron: + v1 = a(tx,-ty,tz), v2 = a(0,2ty,tz), v3 = a(-tx,-ty,tz) + where c=cos(alpha) is the cosine of the angle alpha between + any pair of crystallographic vectors, tx, ty, tz are: + tx=sqrt((1-c)/2), ty=sqrt((1-c)/6), tz=sqrt((1+2c)/3) + -5 Trigonal R, 3fold axis <111> celldm(4)=cos(alpha) + The crystallographic vectors form a three-fold star around + <111>. Defining a' = a/sqrt(3) : + v1 = a' (u,v,v), v2 = a' (v,u,v), v3 = a' (v,v,u) + where u and v are defined as + u = tz - 2*sqrt(2)*ty, v = tz + sqrt(2)*ty + and tx, ty, tz as for case ibrav=5 + Note: if you prefer x,y,z as axis in the cubic limit, + set u = tz + 2*sqrt(2)*ty, v = tz - sqrt(2)*ty + See also the note in Modules/latgen.f90 + + 6 Tetragonal P (st) celldm(3)=c/a + v1 = a(1,0,0), v2 = a(0,1,0), v3 = a(0,0,c/a) + + 7 Tetragonal I (bct) celldm(3)=c/a + v1=(a/2)(1,-1,c/a), v2=(a/2)(1,1,c/a), v3=(a/2)(-1,-1,c/a) + + 8 Orthorhombic P celldm(2)=b/a + celldm(3)=c/a + v1 = (a,0,0), v2 = (0,b,0), v3 = (0,0,c) + + 9 Orthorhombic base-centered(bco) celldm(2)=b/a + celldm(3)=c/a + v1 = (a/2, b/2,0), v2 = (-a/2,b/2,0), v3 = (0,0,c) + -9 as 9, alternate description + v1 = (a/2,-b/2,0), v2 = (a/2, b/2,0), v3 = (0,0,c) + + 10 Orthorhombic face-centered celldm(2)=b/a + celldm(3)=c/a + v1 = (a/2,0,c/2), v2 = (a/2,b/2,0), v3 = (0,b/2,c/2) + + 11 Orthorhombic body-centered celldm(2)=b/a + celldm(3)=c/a + v1=(a/2,b/2,c/2), v2=(-a/2,b/2,c/2), v3=(-a/2,-b/2,c/2) + + 12 Monoclinic P, unique axis c celldm(2)=b/a + celldm(3)=c/a, + celldm(4)=cos(ab) + v1=(a,0,0), v2=(b*cos(gamma),b*sin(gamma),0), v3 = (0,0,c) + where gamma is the angle between axis a and b. +-12 Monoclinic P, unique axis b celldm(2)=b/a + celldm(3)=c/a, + celldm(5)=cos(ac) + v1 = (a,0,0), v2 = (0,b,0), v3 = (c*cos(beta),0,c*sin(beta)) + where beta is the angle between axis a and c + + 13 Monoclinic base-centered celldm(2)=b/a + celldm(3)=c/a, + celldm(4)=cos(ab) + v1 = ( a/2, 0, -c/2), + v2 = (b*cos(gamma), b*sin(gamma), 0), + v3 = ( a/2, 0, c/2), + where gamma is the angle between axis a and b + + 14 Triclinic celldm(2)= b/a, + celldm(3)= c/a, + celldm(4)= cos(bc), + celldm(5)= cos(ac), + celldm(6)= cos(ab) + v1 = (a, 0, 0), + v2 = (b*cos(gamma), b*sin(gamma), 0) + v3 = (c*cos(beta), c*(cos(alpha)-cos(beta)cos(gamma))/sin(gamma), + c*sqrt( 1 + 2*cos(alpha)cos(beta)cos(gamma) + - cos(alpha)^2-cos(beta)^2-cos(gamma)^2 )/sin(gamma) ) + where alpha is the angle between axis b and c + beta is the angle between axis a and c + gamma is the angle between axis a and b + + + + + + ibrav + + +Crystallographic constants - see the ibrav variable. +Specify either these OR A,B,C,cosAB,cosBC,cosAC NOT both. +Only needed values (depending on "ibrav") must be specified +alat = celldm(1) is the lattice parameter "a" (in BOHR) +If ibrav==0, only celldm(1) is used if present; +cell vectors are read from card CELL_PARAMETERS + + + + + + + + + + + + + + + + + ibrav + + +Traditional crystallographic constants: + + a,b,c in ANGSTROM + cosAB = cosine of the angle between axis a and b (gamma) + cosAC = cosine of the angle between axis a and c (beta) + cosBC = cosine of the angle between axis b and c (alpha) + +The axis are chosen according to the value of ibrav. +Specify either these OR celldm but NOT both. +Only needed values (depending on ibrav) must be specified. + +The lattice parameter alat = A (in ANGSTROM ). + +If ibrav == 0, only A is used if present, and +cell vectors are read from card CELL_PARAMETERS. + + + + + REQUIRED + + +number of atoms in the unit cell (ALL atoms, except if +space_group is set, in which case, INEQUIVALENT atoms) + + + + REQUIRED + + +number of types of atoms in the unit cell + + + + +for an insulator, nbnd = number of valence bands +(nbnd = # of electrons /2); +
for a metal, 20% more (minimum 4 more) + + +Number of electronic states (bands) to be calculated. +Note that in spin-polarized calculations the number of +k-point, not the number of bands per k-point, is doubled + + + + 0.0 + + +Total charge of the system. Useful for simulations with charged cells. +By default the unit cell is assumed to be neutral (tot_charge=0). +tot_charge=+1 means one electron missing from the system, +tot_charge=-1 means one additional electron, and so on. + +In a periodic calculation a compensating jellium background is +inserted to remove divergences if the cell is not neutral. + + + + -1 [unspecified] + + +Total majority spin charge - minority spin charge. +Used to impose a specific total electronic magnetization. +If unspecified then tot_magnetization variable is ignored and +the amount of electronic magnetization is determined during +the self-consistent cycle. + + + + +Starting spin polarization on atomic type 'i' in a spin +polarized calculation. Values range between -1 (all spins +down for the valence electrons of atom type 'i') to 1 +(all spins up). Breaks the symmetry and provides a starting +point for self-consistency. The default value is zero, BUT a +value MUST be specified for AT LEAST one atomic type in spin +polarized calculations, unless you constrain the magnetization +(see tot_magnetization and constrained_magnetization). +Note that if you start from zero initial magnetization, you +will invariably end up in a nonmagnetic (zero magnetization) +state. If you want to start from an antiferromagnetic state, +you may need to define two different atomic species +corresponding to sublattices of the same atomic type. +starting_magnetization is ignored if you are performing a +non-scf calculation, if you are restarting from a previous +run, or restarting from an interrupted run. +If you fix the magnetization with tot_magnetization, +you should not specify starting_magnetization. +In the spin-orbit case starting with zero +starting_magnetization on all atoms imposes time reversal +symmetry. The magnetization is never calculated and +kept zero (the internal variable domag is .FALSE.). + + + + REQUIRED + + +kinetic energy cutoff (Ry) for wavefunctions + + + + 4 * ecutwfc + + +Kinetic energy cutoff (Ry) for charge density and potential +For norm-conserving pseudopotential you should stick to the +default value, you can reduce it by a little but it will +introduce noise especially on forces and stress. +If there are ultrasoft PP, a larger value than the default is +often desirable (ecutrho = 8 to 12 times ecutwfc, typically). +PAW datasets can often be used at 4*ecutwfc, but it depends +on the shape of augmentation charge: testing is mandatory. +The use of gradient-corrected functional, especially in cells +with vacuum, or for pseudopotential without non-linear core +correction, usually requires an higher values of ecutrho +to be accurately converged. + + + + ecutrho + + +Kinetic energy cutoff (Ry) for the exact exchange operator in +EXX type calculations. By default this is the same as ecutrho +but in some EXX calculations significant speed-up can be found +by reducing ecutfock, at the expense of some loss in accuracy. +Must be .gt. ecutwfc. Not implemented for stress calculation. +Use with care, especially in metals where it may give raise +to instabilities. + + + + + + + + + + +Three-dimensional FFT mesh (hard grid) for charge +density (and scf potential). If not specified +the grid is calculated based on the cutoff for +charge density (see also ecutrho) +Note: you must specify all three dimensions for this setting to +be used. + + + + + + + + + + +Three-dimensional mesh for wavefunction FFT and for the smooth +part of charge density ( smooth grid ). +Coincides with nr1, nr2, nr3 if ecutrho = 4 * ecutwfc ( default ) +Note: you must specify all three dimensions for this setting to +be used. + + + + .FALSE. + + +if (.TRUE.) symmetry is not used, which means that: + +- if a list of k points is provided in input, it is used + "as is": symmetry-inequivalent k-points are not generated, + and the charge density is not symmetrized; + +- if a uniform (Monkhorst-Pack) k-point grid is provided in + input, it is expanded to cover the entire Brillouin Zone, + irrespective of the crystal symmetry. + Time reversal symmetry is assumed so k and -k are considered + as equivalent unless noinv=.true. is specified. + +A careful usage of this option can be advantageous: +- in low-symmetry large cells, if you cannot afford a k-point + grid with the correct symmetry +- in MD simulations +- in calculations for isolated atoms + + + + .FALSE. + + +if (.TRUE.) symmetry is not used, and k points are +forced to have the symmetry of the Bravais lattice; +an automatically generated Monkhorst-Pack grid will contain +all points of the grid over the entire Brillouin Zone, +plus the points rotated by the symmetries of the Bravais +lattice which were not in the original grid. The same +applies if a k-point list is provided in input instead +of a Monkhorst-Pack grid. Time reversal symmetry is assumed +so k and -k are equivalent unless noinv=.true. is specified. +This option differs from nosym because it forces k-points +in all cases to have the full symmetry of the Bravais lattice +(not all uniform grids have such property!) + + + + .FALSE. + + +if (.TRUE.) disable the usage of k => -k symmetry +(time reversal) in k-point generation + + + + .FALSE. + + +if (.TRUE.) disable the usage of magnetic symmetry operations +that consist in a rotation + time reversal. + + + + .FALSE. + + +if (.TRUE.) force the symmetry group to be symmorphic by disabling +symmetry operations having an associated fractionary translation + + + + .FALSE. + + +if (.TRUE.) do not discard symmetry operations with an +associated fractionary translation that does not send the +real-space FFT grid into itself. These operations are +incompatible with real-space symmetrization but not with the +new G-space symmetrization. BEWARE: do not use for phonons +and for hybrid functionals! Both still use symmetrization +in real space. + + + + + Available options are: + + +gaussian smearing for metals; +see variables smearing and degauss + + +Tetrahedron method, Bloechl's version: +P.E. Bloechl, PRB 49, 16223 (1994) +Requires uniform grid of k-points, to be +automatically generated (see card K_POINTS). +Well suited for calculation of DOS, +less so (because not variational) for +force/optimization/dynamics calculations. + + +Original linear tetrahedron method. +To be used only as a reference; +the optimized tetrahedron method is more efficient. + + +Optimized tetrahedron method: +see M. Kawamura, PRB 89, 094515 (2014). +Can be used for phonon calculations as well. + + +for insulators with a gap + + +The occupation are read from input file, +card OCCUPATIONS. Option valid only for a +single k-point, requires nbnd to be set +in input. Occupations should be consistent +with the value of tot_charge. + + + + + .FALSE. + + +This flag is used for isolated atoms (nat=1) together with +occupations='from_input'. If it is .TRUE., the wavefunctions +are ordered as the atomic starting wavefunctions, independently +from their eigenvalue. The occupations indicate which atomic +states are filled. + +The order of the states is written inside the UPF pseudopotential file. +In the scalar relativistic case: +S -> l=0, m=0 +P -> l=1, z, x, y +D -> l=2, r^2-3z^2, xz, yz, xy, x^2-y^2 + +In the noncollinear magnetic case (with or without spin-orbit), +each group of states is doubled. For instance: +P -> l=1, z, x, y for spin up, l=1, z, x, y for spin down. +Up and down is relative to the direction of the starting +magnetization. + +In the case with spin-orbit and time-reversal +(starting_magnetization=0.0) the atomic wavefunctions are +radial functions multiplied by spin-angle functions. +For instance: +P -> l=1, j=1/2, m_j=-1/2,1/2. l=1, j=3/2, + m_j=-3/2, -1/2, 1/2, 3/2. + +In the magnetic case with spin-orbit the atomic wavefunctions +can be forced to be spin-angle functions by setting +starting_spin_angle to .TRUE.. + + + + .FALSE. + + +In the spin-orbit case when domag=.TRUE., by default, +the starting wavefunctions are initialized as in scalar +relativistic noncollinear case without spin-orbit. + +By setting starting_spin_angle=.TRUE. this behaviour can +be changed and the initial wavefunctions are radial +functions multiplied by spin-angle functions. + +When domag=.FALSE. the initial wavefunctions are always +radial functions multiplied by spin-angle functions +independently from this flag. + +When lspinorb is .FALSE. this flag is not used. + + + + 0.D0 Ry + + +value of the gaussian spreading (Ry) for brillouin-zone +integration in metals. + + + + 'gaussian' + + + +Available options are: + + +ordinary Gaussian spreading (Default) + + +Methfessel-Paxton first-order spreading +(see PRB 40, 3616 (1989)). + + +Marzari-Vanderbilt cold smearing +(see PRL 82, 3296 (1999)) + + +smearing with Fermi-Dirac function + + + + + 1 + + +nspin = 1 : non-polarized calculation (default) + +nspin = 2 : spin-polarized calculation, LSDA + (magnetization along z axis) + +nspin = 4 : spin-polarized calculation, noncollinear + (magnetization in generic direction) + DO NOT specify nspin in this case; + specify noncolin=.TRUE. instead + + + + .false. + + +if .true. the program will perform a noncollinear calculation. + + + + 0.0 + + q2sigma + + + + 0.0 + + q2sigma + + + + 0.1 + + +ecfixed, qcutz, q2sigma: parameters for modified functional to be +used in variable-cell molecular dynamics (or in stress calculation). +"ecfixed" is the value (in Rydberg) of the constant-cutoff; +"qcutz" and "q2sigma" are the height and the width (in Rydberg) +of the energy step for reciprocal vectors whose square modulus +is greater than "ecfixed". In the kinetic energy, G^2 is +replaced by G^2 + qcutz * (1 + erf ( (G^2 - ecfixed)/q2sigma) ) +See: M. Bernasconi et al, J. Phys. Chem. Solids 56, 501 (1995), +doi:10.1016/0022-3697(94)00228-2 + + + + read from pseudopotential files + + +Exchange-correlation functional: eg 'PBE', 'BLYP' etc +See Modules/funct.f90 for allowed values. +Overrides the value read from pseudopotential files. +Use with care and if you know what you are doing! + + + + it depends on the specified functional + + +Fraction of EXX for hybrid functional calculations. In the case of +input_dft='PBE0', the default value is 0.25, while for input_dft='B3LYP' +the exx_fraction default value is 0.20. + + + + 0.106 + + +screening_parameter for HSE like hybrid functionals. +For more information, see: +J. Chem. Phys. 118, 8207 (2003), doi:10.1063/1.1564060 +J. Chem. Phys. 124, 219906 (2006), doi:10.1063/1.2204597 + + + + 'gygi-baldereschi' + + + +Specific for EXX. It selects the kind of approach to be used +for treating the Coulomb potential divergencies at small q vectors. + + appropriate for cubic and quasi-cubic supercells + + appropriate for cubic and quasi-cubic supercells + + appropriate for strongly anisotropic supercells, see also ecutvcut. + + sets Coulomb potential at G,q=0 to 0.0 (required for GAU-PBE) + + + + + .true. + + +Specific for EXX. If .true., extrapolate the G=0 term of the +potential (see README in examples/EXX_example for more) +Set this to .false. for GAU-PBE. + + + + 0.0 Ry + + exxdiv_treatment + + +Reciprocal space cutoff for correcting Coulomb potential +divergencies at small q vectors. + + + + + + + + + + +Three-dimensional mesh for q (k1-k2) sampling of +the Fock operator (EXX). Can be smaller than +the number of k-points. + +Currently this defaults to the size of the k-point mesh used. +In QE =< 5.0.2 it defaulted to nqx1=nqx2=nqx3=1. + + + + .FALSE. + + +DFT+U (formerly known as LDA+U) currently works only for +a few selected elements. Modify Modules/set_hubbard_l.f90 and +PW/src/tabd.f90 if you plan to use DFT+U with an element that +is not configured there. + + +Specify lda_plus_u = .TRUE. to enable DFT+U calculations +See: Anisimov, Zaanen, and Andersen, PRB 44, 943 (1991); + Anisimov et al., PRB 48, 16929 (1993); + Liechtenstein, Anisimov, and Zaanen, PRB 52, R5467 (1994). +You must specify, for each species with a U term, the value of +U and (optionally) alpha, J of the Hubbard model (all in eV): +see lda_plus_u_kind, Hubbard_U, Hubbard_alpha, Hubbard_J + + + + 0 + + +Specifies the type of DFT+U calculation: + + 0 simplified version of Cococcioni and de Gironcoli, + PRB 71, 035105 (2005), using Hubbard_U + + 1 rotationally invariant scheme of Liechtenstein et al., + using Hubbard_U and Hubbard_J + + + + 0.D0 for all species + + +Hubbard_U(i): U parameter (eV) for species i, DFT+U calculation + + + + 0.D0 for all species + + +Hubbard_J0(i): J0 parameter (eV) for species i, DFT+U+J calculation, +see PRB 84, 115108 (2011) for details. + + + + 0.D0 for all species + + +Hubbard_alpha(i) is the perturbation (on atom i, in eV) +used to compute U with the linear-response method of +Cococcioni and de Gironcoli, PRB 71, 35105 (2005) +(only for lda_plus_u_kind=0) + + + + 0.D0 for all species + + +Hubbard_beta(i) is the perturbation (on atom i, in eV) +used to compute J0 with the linear-response method of +Cococcioni and de Gironcoli, PRB 71, 35105 (2005) +(only for lda_plus_u_kind=0). See also +PRB 84, 115108 (2011). + + + + 0.D0 for all species + + +Hubbard_J(i,ityp): J parameters (eV) for species ityp, +used in DFT+U calculations (only for lda_plus_u_kind=1) +For p orbitals: J = Hubbard_J(1,ityp); +For d orbitals: J = Hubbard_J(1,ityp), B = Hubbard_J(2,ityp); +For f orbitals: J = Hubbard_J(1,ityp), E2 = Hubbard_J(2,ityp), + E3= Hubbard_J(3,ityp). +If B or E2 or E3 are not specified or set to 0 they will be +calculated from J using atomic ratios. + + + + -1.d0 that means NOT SET + + +In the first iteration of an DFT+U run it overwrites +the m-th eigenvalue of the ns occupation matrix for the +ispin component of atomic species I. Leave unchanged +eigenvalues that are not set. This is useful to suggest +the desired orbital occupations when the default choice +takes another path. + + + + 'atomic' + + + +Only active when lda_plus_U is .true., specifies the type +of projector on localized orbital to be used in the DFT+U +scheme. + +Currently available choices: + + use atomic wfc's (as they are) to build the projector + + use Lowdin orthogonalized atomic wfc's + + +Lowdin normalization of atomic wfc. Keep in mind: +atomic wfc are not orthogonalized in this case. +This is a "quick and dirty" trick to be used when +atomic wfc from the pseudopotential are not +normalized (and thus produce occupation whose +value exceeds unity). If orthogonalized wfc are +not needed always try 'atomic' first. + + +use the information from file "prefix".atwfc that must +have been generated previously, for instance by pmw.x +(see PP/src/poormanwannier.f90 for details). + + +use the pseudopotential projectors. The charge density +outside the atomic core radii is excluded. +N.B.: for atoms with +U, a pseudopotential with the +all-electron atomic wavefunctions is required (i.e., +as generated by ld1.x with lsave_wfc flag). + + +NB: forces and stress currently implemented only for the +'atomic' and 'pseudo' choice. + + + + + +The direction of the electric field or dipole correction is +parallel to the bg(:,edir) reciprocal lattice vector, so the +potential is constant in planes defined by FFT grid points; +edir = 1, 2 or 3. Used only if tefield is .TRUE. + + + + 0.5D0 + + +Position of the maximum of the saw-like potential along crystal +axis edir, within the unit cell (see below), 0 < emaxpos < 1 +Used only if tefield is .TRUE. + + + + 0.1D0 + + +Zone in the unit cell where the saw-like potential decreases. +( see below, 0 < eopreg < 1 ). Used only if tefield is .TRUE. + + + + 0.001 a.u. + + +Amplitude of the electric field, in ***Hartree*** a.u.; +1 a.u. = 51.4220632*10^10 V/m. Used only if tefield==.TRUE. +The saw-like potential increases with slope eamp in the +region from (emaxpos+eopreg-1) to (emaxpos), then decreases +to 0 until (emaxpos+eopreg), in units of the crystal +vector edir. Important: the change of slope of this +potential must be located in the empty region, or else +unphysical forces will result. + + + + +The angle expressed in degrees between the initial +magnetization and the z-axis. For noncollinear calculations +only; index i runs over the atom types. + + + + +The angle expressed in degrees between the projection +of the initial magnetization on x-y plane and the x-axis. +For noncollinear calculations only. + + + + lambda, fixed_magnetization + + 'none' + + + +Used to perform constrained calculations in magnetic systems. +Currently available choices: + + +no constraint + + +total magnetization is constrained by +adding a penalty functional to the total energy: + +LAMBDA * SUM_{i} ( magnetization(i) - fixed_magnetization(i) )**2 + +where the sum over i runs over the three components of +the magnetization. Lambda is a real number (see below). +Noncolinear case only. Use tot_magnetization for LSDA + + +atomic magnetization are constrained to the defined +starting magnetization adding a penalty: + +LAMBDA * SUM_{i,itype} ( magnetic_moment(i,itype) - mcons(i,itype) )**2 + +where i runs over the cartesian components (or just z +in the collinear case) and itype over the types (1-ntype). +mcons(:,:) array is defined from starting_magnetization, +(and angle1, angle2 in the non-collinear case). lambda is +a real number + + +the angle theta of the total magnetization +with the z axis (theta = fixed_magnetization(3)) +is constrained: + +LAMBDA * ( arccos(magnetization(3)/mag_tot) - theta )**2 + +where mag_tot is the modulus of the total magnetization. + + +not all the components of the atomic +magnetic moment are constrained but only the cosine +of angle1, and the penalty functional is: + +LAMBDA * SUM_{itype} ( mag_mom(3,itype)/mag_mom_tot - cos(angle1(ityp)) )**2 + + +N.B.: symmetrization may prevent to reach the desired orientation +of the magnetization. Try not to start with very highly symmetric +configurations or use the nosym flag (only as a last remedy) + + + + + constrained_magnetization + + 0.d0 + + +total magnetization vector (x,y,z components) to be kept +fixed when constrained_magnetization=='total' + + + + constrained_magnetization + + 1.d0 + + +parameter used for constrained_magnetization calculations +N.B.: if the scf calculation does not converge, try to reduce lambda + to obtain convergence, then restart the run with a larger lambda + + + + 100 + + +Number of iterations after which the program +writes all the atomic magnetic moments. + + + + +if .TRUE. the noncollinear code can use a pseudopotential with +spin-orbit. + + + + 'none' + + + +Used to perform calculation assuming the system to be +isolated (a molecule or a cluster in a 3D supercell). + +Currently available choices: + + +(default): regular periodic calculation w/o any correction. + + +the Makov-Payne correction to the +total energy is computed. An estimate of the vacuum +level is also calculated so that eigenvalues can be +properly aligned. ONLY FOR CUBIC SYSTEMS (ibrav=1,2,3). +Theory: G.Makov, and M.C.Payne, + "Periodic boundary conditions in ab initio + calculations" , PRB 51, 4014 (1995). + + +Martyna-Tuckerman correction +to both total energy and scf potential. Adapted from: +G.J. Martyna, and M.E. Tuckerman, +"A reciprocal space based method for treating long +range interactions in ab-initio and force-field-based +calculation in clusters", J. Chem. Phys. 110, 2810 (1999), +doi:10.1063/1.477923. + + +Effective Screening Medium Method. +For polarized or charged slab calculation, embeds +the simulation cell within an effective semi- +infinite medium in the perpendicular direction +(along z). Embedding regions can be vacuum or +semi-infinite metal electrodes (use esm_bc to +choose boundary conditions). If between two +electrodes, an optional electric field +('esm_efield') may be applied. Method described in +M. Otani and O. Sugino, "First-principles calculations +of charged surfaces and interfaces: A plane-wave +nonrepeated slab approach", PRB 73, 115407 (2006). + +NB: + - Two dimensional (xy plane) average charge density + and electrostatic potentials are printed out to + 'prefix.esm1'. + + - Requires cell with a_3 lattice vector along z, + normal to the xy plane, with the slab centered + around z=0. Also requires symmetry checking to be + disabled along z, either by setting nosym = .TRUE. + or by very slight displacement (i.e., 5e-4 a.u.) + of the slab along z. + +See esm_bc, esm_efield, esm_w, esm_nfit. + + + + + assume_isolated + + 'pbc' + + + +If assume_isolated = 'esm', determines the boundary +conditions used for either side of the slab. + +Currently available choices: + + (default): regular periodic calculation (no ESM). + + Vacuum-slab-vacuum (open boundary conditions). + + +Metal-slab-metal (dual electrode configuration). +See also esm_efield. + + Vacuum-slab-metal + + + + + assume_isolated + + 0.d0 + + +If assume_isolated = 'esm', determines the position offset +[in a.u.] of the start of the effective screening region, +measured relative to the cell edge. (ESM region begins at +z = +/- [L_z/2 + esm_w] ). + + + + assume_isolated + + 0.d0 + + +If assume_isolated = 'esm' and esm_bc = 'bc2', gives the +magnitude of the electric field [Ry/a.u.] to be applied +between semi-infinite ESM electrodes. + + + + assume_isolated + + 4 + + +If assume_isolated = 'esm', gives the number of z-grid points +for the polynomial fit along the cell edge. + + + + lfcpopt + + 0.d0 + + +If lfcpopt = .TRUE., gives the target Fermi energy [Ry]. One can start +with appropriate total charge of the system by giving 'tot_charge'. + + + + 'none' + + +london_s6, london_rcut, london_c6, london_rvdw, ts_vdw_econv_thr, ts_vdw_isolated, xdm_a1, xdm_a2 + + + +Type of Van der Waals correction. Allowed values: + + +Semiempirical Grimme's DFT-D2. +Optional variables: london_s6, london_rcut, london_c6, london_rvdw, +S. Grimme, J. Comp. Chem. 27, 1787 (2006), doi:10.1002/jcc.20495 +V. Barone et al., J. Comp. Chem. 30, 934 (2009), doi:10.1002/jcc.21112 + + +Tkatchenko-Scheffler dispersion corrections with first-principle derived +C6 coefficients (implemented in CP only). +Optional variables: ts_vdw_econv_thr, ts_vdw_isolated +See A. Tkatchenko and M. Scheffler, PRL 102, 073005 (2009). + + +Exchange-hole dipole-moment model. Optional variables: xdm_a1, xdm_a2 +A. D. Becke et al., J. Chem. Phys. 127, 154108 (2007), doi:10.1063/1.2795701 +A. Otero de la Roza et al., J. Chem. Phys. 136, 174109 (2012), +doi:10.1063/1.4705760 + + Note that non-local functionals (eg vdw-DF) are NOT specified here but in input_dft + + + + + .FALSE. + + +OBSOLESCENT, same as vdw_corr='DFT-D' + + + + 0.75 + + +global scaling parameter for DFT-D. Default is good for PBE. + + + + standard Grimme-D2 values + + +atomic C6 coefficient of each atom type + +( if not specified default values from S. Grimme, J. Comp. Chem. 27, 1787 (2006), + doi:10.1002/jcc.20495 are used; see file Modules/mm_dispersion.f90 ) + + + + standard Grimme-D2 values + + +atomic vdw radii of each atom type + +( if not specified default values from S. Grimme, J. Comp. Chem. 27, 1787 (2006), + doi:10.1002/jcc.20495 are used; see file Modules/mm_dispersion.f90 ) + + + + 200 + + +cutoff radius (a.u.) for dispersion interactions + + + + 1.D-6 + + +Optional: controls the convergence of the vdW energy (and forces). The default value +is a safe choice, likely too safe, but you do not gain much in increasing it + + + + .FALSE. + + +Optional: set it to .TRUE. when computing the Tkatchenko-Scheffler vdW energy +for an isolated (non-periodic) system. + + + + .FALSE. + + +OBSOLESCENT, same as vdw_corr='xdm' + + + + 0.6836 + + +Damping function parameter a1 (adimensional). This value should change +with the exchange-correlation functional. The default corresponds to +PW86PBE. +For other functionals, see: + http://schooner.chem.dal.ca/wiki/XDM + A. Otero de la Roza, E. R. Johnson, J. Chem. Phys. 138, 204109 (2013), + doi:10.1063/1.4705760 + + + + 1.5045 + + +Damping function parameter a2 (angstrom). This value should change +with the exchange-correlation functional. The default corresponds to +PW86PBE. +For other functionals, see: + http://schooner.chem.dal.ca/wiki/XDM + A. Otero de la Roza, E. R. Johnson, J. Chem. Phys. 138, 204109 (2013), + doi:10.1063/1.4705760 + + + + 0 + + +The number of the space group of the crystal, as given +in the International Tables of Crystallography A (ITA). +This allows to give in input only the inequivalent atomic +positions. The positions of all the symmetry equivalent atoms +are calculated by the code. Used only when the atomic positions +are of type crystal_sg. + + + + .FALSE. + + +Used only for monoclinic lattices. If .TRUE. the b +unique ibrav (-12 or -13) are used, and symmetry +equivalent positions are chosen assuming that the +two fold axis or the mirror normal is parallel to the +b axis. If .FALSE. it is parallel to the c axis. + + + + 1 + + +Used only for space groups that in the ITA allow +the use of two different origins. origin_choice=1, +means the first origin, while origin_choice=2 is the +second origin. + + + + .TRUE. + + +Used only for rhombohedral space groups. +When .TRUE. the coordinates of the inequivalent atoms are +given with respect to the rhombohedral axes, when .FALSE. +the coordinates of the inequivalent atoms are given with +respect to the hexagonal axes. They are converted internally +to the rhombohedral axes and ibrav=5 is used in both cases. + + + + + + 0.5 + + +used only if monopole = .TRUE. +Specifies the position of the charged plate which represents +the counter charge in doped systems (tot_charge .ne. 0). +In units of the unit cell length in z direction, zmon in ]0,1[ +Details of the monopole potential can be found in +T. Brumme, M. Calandra, F. Mauri; PRB 89, 245406 (2014). + + + + .FALSE. + + +used only if monopole = .TRUE. +Allows the relaxation of the system towards the charged plate. +Use carefully and utilize either a layer of fixed atoms or a +potential barrier (block=.TRUE.) to avoid the atoms moving to +the position of the plate or the dipole of the dipole +correction (dipfield=.TRUE.). + + + + .FALSE. + + +used only if monopole = .TRUE. +Adds a potential barrier to the total potential seen by the +electrons to mimic a dielectric in field effect configuration +and/or to avoid electrons spilling into the vacuum region for +electron doping. Potential barrier is from block_1 to block_2 and +has a height of block_height. +If dipfield = .TRUE. then eopreg is used for a smooth increase and +decrease of the potential barrier. + + + + 0.45 + + +used only if monopole = .TRUE. and block = .TRUE. +lower beginning of the potential barrier, in units of the +unit cell size along z, block_1 in ]0,1[ + + + + 0.55 + + +used only if monopole = .TRUE. and block = .TRUE. +upper beginning of the potential barrier, in units of the +unit cell size along z, block_2 in ]0,1[ + + + + 0.1 + + +used only if monopole = .TRUE. and block = .TRUE. +Height of the potential barrier in Rydberg. + + + + + + + 100 + + +maximum number of iterations in a scf step + + + + .TRUE. + + +If .false. do not stop molecular dynamics or ionic relaxation +when electron_maxstep is reached. Use with care. + + + + 1.D-6 + + +Convergence threshold for selfconsistency: + estimated energy error < conv_thr +(note that conv_thr is extensive, like the total energy). + +For non-self-consistent calculations, conv_thr is used +to set the default value of the threshold (ethr) for +iterative diagonalizazion: see diago_thr_init + + + + .FALSE + + +If .TRUE. this turns on the use of an adaptive conv_thr for +the inner scf loops when using EXX. + + + + 1.D-3 + + +When adaptive_thr = .TRUE. this is the convergence threshold +used for the first scf cycle. + + + + 1.D-1 + + +When adaptive_thr = .TRUE. the convergence threshold for +each scf cycle is given by: +max( conv_thr, conv_thr_multi * dexx ) + + + + 'plain' + + + Available options are: + + charge density Broyden mixing + + +as above, with simple Thomas-Fermi screening +(for highly homogeneous systems) + + +as above, with local-density-dependent TF screening +(for highly inhomogeneous systems) + + + + + 0.7D0 + + +mixing factor for self-consistency + + + + 8 + + +number of iterations used in mixing scheme. +If you are tight with memory, you may reduce it to 4 or so. + + + + 0 + + +For DFT+U : number of iterations with fixed ns ( ns is the +atomic density appearing in the Hubbard term ). + + + + 'david' + + + Available options are: + + +Davidson iterative diagonalization with overlap matrix +(default). Fast, may in some rare cases fail. + + +Conjugate-gradient-like band-by-band diagonalization. +Typically slower than 'david' but it uses less memory +and is more robust (it seldom fails). + + +OBSOLETE, use -ndiag 1 instead. +The subspace diagonalization in Davidson is performed +by a fully distributed-memory parallel algorithm on +4 or more processors, by default. The allocated memory +scales down with the number of procs. Procs involved +in diagonalization can be changed with command-line +option -ndiag N. On multicore CPUs it is often +convenient to let just one core per CPU to work +on linear algebra. + + + + + 0 + + OBSOLETE: use command-line option "-ndiag XX" instead + + + + +Convergence threshold (ethr) for iterative diagonalization +(the check is on eigenvalue convergence). + +For scf calculations: default is 1.D-2 if starting from a +superposition of atomic orbitals; 1.D-5 if starting from a +charge density. During self consistency the threshold +is automatically reduced (but never below 1.D-13) when +approaching convergence. + +For non-scf calculations: default is (conv_thr/N elec)/10. + + + + +For conjugate gradient diagonalization: max number of iterations + + + + 4 + + +For Davidson diagonalization: dimension of workspace +(number of wavefunction packets, at least 2 needed). +A larger value may yield a smaller number of iterations in +the algorithm but uses more memory and more CPU time in +subspace diagonalization. +Try diago_david_ndim=2 if you are tight on memory or if +the time spent in subspace diagonalization (cdiaghg/rdiaghg) +is significant compared to the time spent in h_psi + + + + .FALSE. + + +If .TRUE. all the empty states are diagonalized at the same level +of accuracy of the occupied ones. Otherwise the empty states are +diagonalized using a larger threshold (this should not affect +total energy, forces, and other ground-state properties). + + + + 0.D0 + + +Amplitude of the finite electric field (in Ry a.u.; +1 a.u. = 36.3609*10^10 V/m). Used only if lelfield==.TRUE. +and if k-points (K_POINTS card) are not automatic. + + + + (0.D0, 0.D0, 0.D0) + + +Finite electric field (in Ry a.u.=36.3609*10^10 V/m) in +cartesian axis. Used only if lelfield==.TRUE. and if +k-points (K_POINTS card) are automatic. + + + + 'none' + + + Available options are: + + +set the zero of the electronic polarization (with lelfield==.true..) +to the result of a previous calculation + + +write on disk data on electronic polarization to be read in another +calculation + + +none of the above points + + + + + + Available options are: + + +starting potential from atomic charge superposition +(default for scf, *relax, *md) + + +start from existing "charge-density.xml" file in the +directory specified by variables prefix and outdir +For nscf and bands calculation this is the default +and the only sensible possibility. + + + + + 'atomic+random' + + + Available options are: + + +Start from superposition of atomic orbitals. +If not enough atomic orbitals are available, +fill with random numbers the remaining wfcs +The scf typically starts better with this option, +but in some high-symmetry cases one can "loose" +valence states, ending up in the wrong ground state. + + +As above, plus a superimposed "randomization" +of atomic orbitals. Prevents the "loss" of states +mentioned above. + + +Start from random wfcs. Slower start of scf but safe. +It may also reduce memory usage in conjunction with +diagonalization='cg'. + + +Start from an existing wavefunction file in the +directory specified by variables prefix and outdir. + + + + + .FALSE. + + +If .true., use the real-space algorithm for augmentation +charges in ultrasoft pseudopotentials. +Must faster execution of ultrasoft-related calculations, +but numerically less accurate than the default algorithm. +Use with care and after testing! + + + + + + + + +Specify the type of ionic dynamics. + +For different type of calculation different possibilities are +allowed and different default values apply: + +CASE ( calculation == 'relax' ) + + +(default) use BFGS quasi-newton algorithm, +based on the trust radius procedure, +for structural relaxation + + +use damped (quick-min Verlet) +dynamics for structural relaxation +Can be used for constrained +optimisation: see CONSTRAINTS card + + +CASE ( calculation == 'md' ) + + +(default) use Verlet algorithm to integrate +Newton's equation. For constrained +dynamics, see CONSTRAINTS card + + +ion dynamics is over-damped Langevin + + +over-damped Langevin with Smart Monte Carlo: +see R.J. Rossky, JCP, 69, 4628 (1978), doi:10.1063/1.436415 + + +CASE ( calculation == 'vc-relax' ) + + +(default) use BFGS quasi-newton algorithm; +cell_dynamics must be 'bfgs' too + + +use damped (Beeman) dynamics for +structural relaxation + + +CASE ( calculation == 'vc-md' ) + + +(default) use Beeman algorithm to integrate +Newton's equation + + + + + 'default' + + + Available options are: + + +if restarting, use atomic positions read from the +restart file; in all other cases, use atomic +positions from standard input. + + +restart the simulation with atomic positions read +from standard input, even if restarting. + + + + + 'atomic' + + + +Used to extrapolate the potential from preceding ionic steps. + + no extrapolation + + +extrapolate the potential as if it was a sum of +atomic-like orbitals + + +extrapolate the potential with first-order +formula + + +as above, with second order formula + + +Note: 'first_order' and 'second-order' extrapolation make sense +only for molecular dynamics calculations + + + + + 'none' + + + +Used to extrapolate the wavefunctions from preceding ionic steps. + + no extrapolation + + +extrapolate the wave-functions with first-order formula. + + +as above, with second order formula. + + +Note: 'first_order' and 'second-order' extrapolation make sense +only for molecular dynamics calculations + + + + + .FALSE. + + +This keyword is useful when simulating the dynamics and/or the +thermodynamics of an isolated system. If set to true the total +torque of the internal forces is set to zero by adding new forces +that compensate the spurious interaction with the periodic +images. This allows for the use of smaller supercells. + +BEWARE: since the potential energy is no longer consistent with +the forces (it still contains the spurious interaction with the +repeated images), the total energy is not conserved anymore. +However the dynamical and thermodynamical properties should be +in closer agreement with those of an isolated system. +Also the final energy of a structural relaxation will be higher, +but the relaxation itself should be faster. + + + + + + 'not_controlled' + + + Available options are: + + +control ionic temperature via velocity rescaling +(first method) see parameters tempw, tolp, and +nraise (for VC-MD only). This rescaling method +is the only one currently implemented in VC-MD + + +control ionic temperature via velocity rescaling +(second method) see parameters tempw and nraise + + +control ionic temperature via velocity rescaling +(third method) see parameter delta_t + + +reduce ionic temperature every nraise steps +by the (negative) value delta_t + + +control ionic temperature using "soft" velocity +rescaling - see parameters tempw and nraise + + +control ionic temperature using Andersen thermostat +see parameters tempw and nraise + + +initialize ion velocities to temperature tempw +and leave uncontrolled further on + + +(default) ionic temperature is not controlled + + + + + 300.D0 + + +Starting temperature (Kelvin) in MD runs +target temperature for most thermostats. + + + + 100.D0 + + +Tolerance for velocity rescaling. Velocities are rescaled if +the run-averaged and target temperature differ more than tolp. + + + + 1.D0 + + +if ion_temperature == 'rescale-T' : + at each step the instantaneous temperature is multiplied + by delta_t; this is done rescaling all the velocities. + +if ion_temperature == 'reduce-T' : + every 'nraise' steps the instantaneous temperature is + reduced by -delta_t (i.e. delta_t < 0 is added to T) + +The instantaneous temperature is calculated at the end of +every ionic move and BEFORE rescaling. This is the temperature +reported in the main output. + +For delta_t < 0, the actual average rate of heating or cooling +should be roughly C*delta_t/(nraise*dt) (C=1 for an +ideal gas, C=0.5 for a harmonic solid, theorem of energy +equipartition between all quadratic degrees of freedom). + + + + 1 + + +if ion_temperature == 'reduce-T' : + every nraise steps the instantaneous temperature is + reduced by -delta_t (i.e. delta_t is added to the temperature) + +if ion_temperature == 'rescale-v' : + every nraise steps the average temperature, computed from + the last nraise steps, is rescaled to tempw + +if ion_temperature == 'rescaling' and calculation == 'vc-md' : + every nraise steps the instantaneous temperature + is rescaled to tempw + +if ion_temperature == 'berendsen' : + the "rise time" parameter is given in units of the time step: + tau = nraise*dt, so dt/tau = 1/nraise + +if ion_temperature == 'andersen' : + the "collision frequency" parameter is given as nu=1/tau + defined above, so nu*dt = 1/nraise + + + + .FALSE. + + +This keyword applies only in the case of molecular dynamics or +damped dynamics. If true the ions are refolded at each step into +the supercell. + + + + + + + 100.D0 + + +Max reduction factor for conv_thr during structural optimization +conv_thr is automatically reduced when the relaxation +approaches convergence so that forces are still accurate, +but conv_thr will not be reduced to less that conv_thr / upscale. + + + + 1 + + +Number of old forces and displacements vectors used in the +PULAY mixing of the residual vectors obtained on the basis +of the inverse hessian matrix given by the BFGS algorithm. +When bfgs_ndim = 1, the standard quasi-Newton BFGS method is +used. +(bfgs only) + + + + 0.8D0 + + +Maximum ionic displacement in the structural relaxation. +(bfgs only) + + + + 1.D-3 + + +Minimum ionic displacement in the structural relaxation +BFGS is reset when trust_radius < trust_radius_min. +(bfgs only) + + + + 0.5D0 + + +Initial ionic displacement in the structural relaxation. +(bfgs only) + + + + 0.01D0 + + w_2 + + + + 0.5D0 + + +Parameters used in line search based on the Wolfe conditions. +(bfgs only) + + + + + + + + + +Specify the type of dynamics for the cell. +For different type of calculation different possibilities +are allowed and different default values apply: + +CASE ( calculation == 'vc-relax' ) + + no dynamics + + steepest descent ( not implemented ) + + +damped (Beeman) dynamics of the Parrinello-Rahman extended lagrangian + + +damped (Beeman) dynamics of the new Wentzcovitch extended lagrangian + + +BFGS quasi-newton algorithm (default) +ion_dynamics must be 'bfgs' too + + +CASE ( calculation == 'vc-md' ) + + no dynamics + + +(Beeman) molecular dynamics of the Parrinello-Rahman extended lagrangian + + +(Beeman) molecular dynamics of the new Wentzcovitch extended lagrangian + + + + + 0.D0 + + +Target pressure [KBar] in a variable-cell md or relaxation run. + + + + +0.75*Tot_Mass/pi**2 for Parrinello-Rahman MD; +0.75*Tot_Mass/pi**2/Omega**(2/3) for Wentzcovitch MD + + +Fictitious cell mass [amu] for variable-cell simulations +(both 'vc-md' and 'vc-relax') + + + + 2.0 for variable-cell calculations, 1.0 otherwise + + +Used in the construction of the pseudopotential tables. +It should exceed the maximum linear contraction of the +cell during a simulation. + + + + 0.5D0 Kbar + + +Convergence threshold on the pressure for variable cell +relaxation ('vc-relax' : note that the other convergence + thresholds for ionic relaxation apply as well). + + + + 'all' + + + +Select which of the cell parameters should be moved: + + all axis and angles are moved + + only the x component of axis 1 (v1_x) is moved + + only the y component of axis 2 (v2_y) is moved + + only the z component of axis 3 (v3_z) is moved + + only v1_x and v2_y are moved + + only v1_x and v3_z are moved + + only v2_y and v3_z are moved + + only v1_x, v2_y, v3_z are moved + + all axis and angles, keeping the volume fixed + + the volume changes, keeping all angles fixed (i.e. only celldm(1) changes) + + only x and y components are allowed to change + + as above, keeping the area in xy plane fixed + + +BEWARE: if axis are not orthogonal, some of these options do not + work (symmetry is broken). If you are not happy with them, + edit subroutine init_dofree in file Modules/cell_base.f90 + + + + + + + + + + +label of the atom. Acceptable syntax: +chemical symbol X (1 or 2 characters, case-insensitive) +or chemical symbol plus a number or a letter, as in +"Xn" (e.g. Fe1) or "X_*" or "X-*" (e.g. C1, C_h; +max total length cannot exceed 3 characters) + + + + +mass of the atomic species [amu: mass of C = 12] +Used only when performing Molecular Dynamics run +or structural optimization runs using Damped MD. +Not actually used in all other cases (but stored +in data files, so phonon calculations will use +these values unless other values are provided) + + + + +File containing PP for this species. + +The pseudopotential file is assumed to be in the new UPF format. +If it doesn't work, the pseudopotential format is determined by +the file name: + +*.vdb or *.van Vanderbilt US pseudopotential code +*.RRKJ3 Andrea Dal Corso's code (old format) +none of the above old PWscf norm-conserving format + + + +
+ + + + + alat | bohr | angstrom | crystal | crystal_sg + + (DEPRECATED) alat + + + +Units for ATOMIC_POSITIONS: + + +atomic positions are in cartesian coordinates, in +units of the lattice parameter (either celldm(1) +or A). If no option is specified, 'alat' is assumed; +not specifying units is DEPRECATED and will no +longer be allowed in the future + + +atomic positions are in cartesian coordinate, +in atomic units (i.e. Bohr radii) + + +atomic positions are in cartesian coordinates, in Angstrom + + +atomic positions are in crystal coordinates, i.e. +in relative coordinates of the primitive lattice +vectors as defined either in card CELL_PARAMETERS +or via the ibrav + celldm / a,b,c... variables + + +atomic positions are in crystal coordinates, i.e. +in relative coordinates of the primitive lattice. +This option differs from the previous one because +in this case only the symmetry inequivalent atoms +are given. The variable space_group must indicate +the space group number used to find the symmetry +equivalent atoms. The other variables that control +this option are uniqueb, origin_choice, and +rhombohedral. + + + + + + +Specified atomic positions will be IGNORED and those from the +previous scf calculation will be used instead !!! + + + + + + + + label of the atom as specified in ATOMIC_SPECIES + + + + +atomic positions + +NOTE: each atomic coordinate can also be specified as a simple algebraic expression. + To be interpreted correctly expression must NOT contain any blank + space and must NOT start with a "+" sign. The available expressions are: + + + (plus), - (minus), / (division), * (multiplication), ^ (power) + + All numerical constants included are considered as double-precision numbers; + i.e. 1/2 is 0.5, not zero. Other functions, such as sin, sqrt or exp are + not available, although sqrt can be replaced with ^(1/2). + + Example: + C 1/3 1/2*3^(-1/2) 0 + + is equivalent to + + C 0.333333 0.288675 0.000000 + + Please note that this feature is NOT supported by XCrysDen (which will + display a wrong structure, or nothing at all). + + When atomic positions are of type crystal_sg coordinates can be given + in the following four forms (Wyckoff positions): + C 1a + C 8g x + C 24m x y + C 48n x y z + The first form must be used when the Wyckoff letter determines uniquely + all three coordinates, forms 2,3,4 when the Wyckoff letter and 1,2,3 + coordinates respectively are needed. + + The forms: + C 8g x x x + C 24m x x y + are not allowed, but + C x x x + C x x y + C x y z + are correct. + + + + + + + + + + + +component i of the force for this atom is multiplied by if_pos(i), +which must be either 0 or 1. Used to keep selected atoms and/or +selected components fixed in MD dynamics or +structural optimization run. + +With crystal_sg atomic coordinates the constraints are copied in all equivalent +atoms. + + 1 + + + + + + + + + + +
+ + + + + + + tpiba | automatic | crystal | gamma | tpiba_b | crystal_b | tpiba_c | crystal_c + + tbipa + + + +K_POINTS options are: + + +read k-points in cartesian coordinates, +in units of 2 pi/a (default) + + +automatically generated uniform grid of k-points, i.e, +generates ( nk1, nk2, nk3 ) grid with ( sk1, sk2, sk3 ) offset. +nk1, nk2, nk3 as in Monkhorst-Pack grids +k1, k2, k3 must be 0 ( no offset ) or 1 ( grid displaced +by half a grid step in the corresponding direction ) +BEWARE: only grids having the full symmetry of the crystal + work with tetrahedra. Some grids with offset may not work. + + +read k-points in crystal coordinates, i.e. in relative +coordinates of the reciprocal lattice vectors + + +use k = 0 (no need to list k-point specifications after card) +In this case wavefunctions can be chosen as real, +and specialized subroutines optimized for calculations +at the gamma point are used (memory and cpu requirements +are reduced by approximately one half). + + +Used for band-structure plots. +k-points are in units of 2 pi/a. +nks points specify nks-1 lines in reciprocal space. +Every couple of points identifies the initial and +final point of a line. pw.x generates N intermediate +points of the line where N is the weight of the first point. + + +As tpiba_b, but k-points are in crystal coordinates. + + +Used for band-structure contour plots. +k-points are in units of 2 pi/a. nks must be 3. +3 k-points k_0, k_1, and k_2 specify a rectangle +in reciprocal space of vertices k_0, k_1, k_2, +k_1 + k_2 - k_0: k_0 + \alpha (k_1-k_0)+ +\beta (k_2-k_0) with 0 <\alpha,\beta < 1. +The code produces a uniform mesh n1 x n2 +k points in this rectangle. n1 and n2 are +the weights of k_1 and k_2. The weight of k_0 +is not used. + + +As tpiba_c, but k-points are in crystal coordinates. + + + + + + + + + Number of supplied special k-points. + + + + + + + + + + + + + + + +Special k-points (xk_x/y/z) in the irreducible Brillouin Zone +(IBZ) of the lattice (with all symmetries) and weights (wk) +See the literature for lists of special points and +the corresponding weights. + +If the symmetry is lower than the full symmetry +of the lattice, additional points with appropriate +weights are generated. Notice that such procedure +assumes that ONLY k-points in the IBZ are provided in input + +In a non-scf calculation, weights do not affect the results. +If you just need eigenvalues and eigenvectors (for instance, +for a band-structure plot), weights can be set to any value +(for instance all equal to 1). + + + +
+ + + + + + + + + + + + + +These parameters specify the k-point grid +(nk1 x nk2 x nk3) as in Monkhorst-Pack grids. + + + + + + + + + + +The grid offsets; sk1, sk2, sk3 must be +0 ( no offset ) or 1 ( grid displaced by +half a grid step in the corresponding direction ). + + + + + + + + + + + + + + alat | bohr | angstrom + + +Unit for lattice vectors; options are: + +'bohr' / 'angstrom': + lattice vectors in bohr-radii / angstrom. + In this case the lattice parameter alat = sqrt(v1*v1). + +'alat' / nothing specified: + lattice vectors in units of the lattice parameter (either + celldm(1) or A). Not specifying units is DEPRECATED + and will not be allowed in the future. + +If neither unit nor lattice parameter are specified, +'bohr' is assumed - DEPRECATED, will no longer be allowed + + + + + + + + +Crystal lattice vectors (in cartesian axis): + v1(1) v1(2) v1(3) ... 1st lattice vector + v2(1) v2(2) v2(3) ... 2nd lattice vector + v3(1) v3(2) v3(3) ... 3rd lattice vector + + + + + + + + + +
+ + + + + +When this card is present the SHAKE algorithm is automatically used. + + + + + Number of constraints. + + + + + Tolerance for keeping the constraints satisfied. + + + + + + + + + +Type of constraint : + + +constraint on global coordination-number, i.e. the +average number of atoms of type B surrounding the +atoms of type A. The coordination is defined by +using a Fermi-Dirac. +(four indexes must be specified). + + +constraint on local coordination-number, i.e. the +average number of atoms of type A surrounding a +specific atom. The coordination is defined by +using a Fermi-Dirac. +(four indexes must be specified). + + +constraint on interatomic distance +(two atom indexes must be specified). + + +constraint on planar angle +(three atom indexes must be specified). + + +constraint on torsional angle +(four atom indexes must be specified). + + +constraint on the projection onto a given direction +of the vector defined by the position of one atom +minus the center of mass of the others. +G. Roma, J.P. Crocombette: J. Nucl. Mater. 403, 32 (2010), +doi:10.1016/j.jnucmat.2010.06.001 + + + + + + + + + + + + + + + +These variables have different meanings for different constraint types: + +'type_coord' : + constr(1) is the first index of the atomic type involved + constr(2) is the second index of the atomic type involved + constr(3) is the cut-off radius for estimating the coordination + constr(4) is a smoothing parameter + +'atom_coord' : + constr(1) is the atom index of the atom with constrained coordination + constr(2) is the index of the atomic type involved in the coordination + constr(3) is the cut-off radius for estimating the coordination + constr(4) is a smoothing parameter + +'distance' : + atoms indices object of the constraint, as they appear in + the ATOMIC_POSITIONS card + +'planar_angle', 'torsional_angle' : + atoms indices object of the constraint, as they appear in the + ATOMIC_POSITIONS card (beware the order) + +'bennett_proj' : + constr(1) is the index of the atom whose position is constrained. + constr(2:4) are the three coordinates of the vector that specifies + the constraint direction. + + + + + +Target for the constrain ( angles are specified in degrees ). +This variable is optional. + + + + +
+ + + + + + + + + +Occupations of individual states (MAX 10 PER ROW). +For spin-polarized calculations, these are majority spin states. + + + + + +Occupations of minority spin states (MAX 10 PER ROW) +To be specified only for spin-polarized calculations. + + + + +
+ + + + + +BEWARE: if the sum of external forces is not zero, the center of mass of + the system will move + + + + + + label of the atom as specified in ATOMIC_SPECIES + + + + +external force on atom X (cartesian components, Ry/a.u. units) + + + + + + + + + +
+ + + diff --git a/aiida_quantumespresso/calculations/helpers/INPUT_PW-6.2.xml b/aiida_quantumespresso/calculations/helpers/INPUT_PW-6.2.xml new file mode 100644 index 000000000..cee9e7e9a --- /dev/null +++ b/aiida_quantumespresso/calculations/helpers/INPUT_PW-6.2.xml @@ -0,0 +1,2992 @@ + + + + + + + + +Input data format: { } = optional, [ ] = it depends, | = or + +All quantities whose dimensions are not explicitly specified are in +RYDBERG ATOMIC UNITS. Charge is "number" charge (i.e. not multiplied +by e); potentials are in energy units (i.e. they are multiplied by e). + +BEWARE: TABS, DOS <CR><LF> CHARACTERS ARE POTENTIAL SOURCES OF TROUBLE + +Namelists must appear in the order given below. +Comment lines in namelists can be introduced by a "!", exactly as in +fortran code. Comments lines in cards can be introduced by +either a "!" or a "#" character in the first position of a line. +Do not start any line in cards with a "/" character. +Leave a space between card names and card options, e.g. +ATOMIC_POSITIONS (bohr), not ATOMIC_POSITIONS(bohr) +Do not start any line in cards with a "/" character. + + +Structure of the input data: +=============================================================================== + +&CONTROL + ... +/ + +&SYSTEM + ... +/ + +&ELECTRONS + ... +/ + +[ &IONS + ... + / ] + +[ &CELL + ... + / ] + +ATOMIC_SPECIES + X Mass_X PseudoPot_X + Y Mass_Y PseudoPot_Y + Z Mass_Z PseudoPot_Z + +ATOMIC_POSITIONS { alat | bohr | crystal | angstrom | crystal_sg } + X 0.0 0.0 0.0 {if_pos(1) if_pos(2) if_pos(3)} + Y 0.5 0.0 0.0 + Z O.0 0.2 0.2 + +K_POINTS { tpiba | automatic | crystal | gamma | tpiba_b | crystal_b | tpiba_c | crystal_c } +if (gamma) + nothing to read +if (automatic) + nk1, nk2, nk3, k1, k2, k3 +if (not automatic) + nks + xk_x, xk_y, xk_z, wk + +[ CELL_PARAMETERS { alat | bohr | angstrom } + v1(1) v1(2) v1(3) + v2(1) v2(2) v2(3) + v3(1) v3(2) v3(3) ] + +[ OCCUPATIONS + f_inp1(1) f_inp1(2) f_inp1(3) ... f_inp1(10) + f_inp1(11) f_inp1(12) ... f_inp1(nbnd) + [ f_inp2(1) f_inp2(2) f_inp2(3) ... f_inp2(10) + f_inp2(11) f_inp2(12) ... f_inp2(nbnd) ] ] + +[ CONSTRAINTS + nconstr { constr_tol } + constr_type(.) constr(1,.) constr(2,.) [ constr(3,.) constr(4,.) ] { constr_target(.) } ] + +[ ATOMIC_FORCES + label_1 Fx(1) Fy(1) Fz(1) + ..... + label_n Fx(n) Fy(n) Fz(n) ] + + + + 'scf' + + + +A string describing the task to be performed. Options are: + + + + + + + + + + + + + + + + +(vc = variable-cell). + + + + + ' ' + + +reprinted on output. + + + + 'low' + + + +Currently two verbosity levels are implemented: + + + + + + +'debug' and 'medium' have the same effect as 'high'; +'default' and 'minimal' as 'low' + + + + + 'from_scratch' + + + Available options are: + + +From scratch. This is the normal way to perform a PWscf calculation + + +From previous interrupted run. Use this switch only if you want to +continue an interrupted calculation, not to start a new one, or to +perform non-scf calculations. Works only if the calculation was +cleanly stopped using variable max_seconds, or by user request +with an "exit file" (i.e.: create a file "prefix".EXIT, in directory +"outdir"; see variables prefix, outdir). Overrides startingwfc +and startingpot. + + + + + .TRUE. + + +This flag controls the way wavefunctions are stored to disk : + +.TRUE. collect wavefunctions from all processors, store them + into the output data directory "outdir"/"prefix".save + The resulting format is portable to a different number + of processor, or different kind of parallelization + +.FALSE. do not collect wavefunctions, leave them in temporary + local files (one per processor). The resulting format + is readable only on the same number of processors and + with the same knd of paralleliztio used to write it. + +Note that this flag has no effect on reading, only on writing. + + + + +number of molecular-dynamics or structural optimization steps +performed in this run + + +1 if calculation == 'scf', 'nscf', 'bands'; +50 for the other cases + + + + write only at convergence + + +band energies are written every iprint iterations + + + + .false. + + +calculate stress. It is set to .TRUE. automatically if +calculation == 'vc-md' or 'vc-relax' + + + + +calculate forces. It is set to .TRUE. automatically if +calculation == 'relax','md','vc-md' + + + + 20.D0 + + +time step for molecular dynamics, in Rydberg atomic units +(1 a.u.=4.8378 * 10^-17 s : beware, the CP code uses + Hartree atomic units, half that much!!!) + + + + +value of the ESPRESSO_TMPDIR environment variable if set; +current directory ('./') otherwise + + +input, temporary, output files are found in this directory, +see also wfcdir + + + + same as outdir + + +This directory specifies where to store files generated by +each processor (*.wfc{N}, *.igk{N}, etc.). Useful for +machines without a parallel file system: set wfcdir to +a local file system, while outdir should be a parallel +or networkfile system, visible to all processors. Beware: +in order to restart from interrupted runs, or to perform +further calculations using the produced data files, you +may need to copy files to outdir. Works only for pw.x. + + + + 'pwscf' + + +prepended to input/output filenames: +prefix.wfc, prefix.rho, etc. + + + + .true. + + +If .false. a subdirectory for each k_point is not opened +in the "prefix".save directory; Kohn-Sham eigenvalues are +stored instead in a single file for all k-points. Currently +doesn't work together with wf_collect + + + + 1.D+7, or 150 days, i.e. no time limit + + +Jobs stops after max_seconds CPU time. Use this option +in conjunction with option restart_mode if you need to +split a job too long to complete into shorter jobs that +fit into your batch queues. + + + + 1.0D-4 + + +Convergence threshold on total energy (a.u) for ionic +minimization: the convergence criterion is satisfied +when the total energy changes less than etot_conv_thr +between two consecutive scf steps. Note that etot_conv_thr +is extensive, like the total energy. +See also forc_conv_thr - both criteria must be satisfied + + + + 1.0D-3 + + +Convergence threshold on forces (a.u) for ionic minimization: +the convergence criterion is satisfied when all components of +all forces are smaller than forc_conv_thr. +See also etot_conv_thr - both criteria must be satisfied + + + + see below + + + +Specifies the amount of disk I/O activity: + + +save all data to disk at each SCF step + + +save wavefunctions at each SCF step unless +there is a single k-point per process (in which +case the behavior is the same as 'low') + + +store wfc in memory, save only at the end + + +do not save anything, not even at the end +('scf', 'nscf', 'bands' calculations; some data +may be written anyway for other calculations) + + +Default is 'low' for the scf case, 'medium' otherwise. +Note that the needed RAM increases as disk I/O decreases! +It is no longer needed to specify 'high' in order to be able +to restart from an interrupted calculation (see restart_mode) +but you cannot restart in disk_io=='none' + + + + + +value of the $ESPRESSO_PSEUDO environment variable if set; +'$HOME/espresso/pseudo/' otherwise + + +directory containing pseudopotential files + + + + .FALSE. + + +If .TRUE. a saw-like potential simulating an electric field +is added to the bare ionic potential. See variables edir, +eamp, emaxpos, eopreg for the form and size of +the added potential. + + + + .FALSE. + + +If .TRUE. and tefield==.TRUE. a dipole correction is also +added to the bare ionic potential - implements the recipe +of L. Bengtsson, PRB 59, 12301 (1999). See variables edir, +emaxpos, eopreg for the form of the correction. Must +be used ONLY in a slab geometry, for surface calculations, +with the discontinuity FALLING IN THE EMPTY SPACE. + + + + .FALSE. + + +If .TRUE. a homogeneous finite electric field described +through the modern theory of the polarization is applied. +This is different from tefield == .true. ! + + + + 1 + + +In the case of a finite electric field ( lelfield == .TRUE. ) +it defines the number of iterations for converging the +wavefunctions in the electric field Hamiltonian, for each +external iteration on the charge density + + + + .FALSE. + + +If .TRUE. perform orbital magnetization calculation. +If finite electric field is applied (lelfield==.true.) only Kubo terms are computed +[for details see New J. Phys. 12, 053032 (2010), doi:10.1088/1367-2630/12/5/053032]. + +The type of calculation is 'nscf' and should be performed on an automatically +generated uniform grid of k points. + +Works ONLY with norm-conserving pseudopotentials. + + + + .FALSE. + + +If .TRUE. perform a Berry phase calculation. +See the header of PW/src/bp_c_phase.f90 for documentation. + + + + +For Berry phase calculation: direction of the k-point +strings in reciprocal space. Allowed values: 1, 2, 3 +1=first, 2=second, 3=third reciprocal lattice vector +For calculations with finite electric fields +(lelfield==.true.) "gdir" is the direction of the field. + + + + +For Berry phase calculation: number of k-points to be +calculated along each symmetry-reduced string. +The same for calculation with finite electric fields +(lelfield==.true.). + + + + fcp_mu + + .FALSE. + + +If .TRUE. perform a constant bias potential (constant-mu) calculation +for a static system with ESM method. See the header of PW/src/fcp.f90 +for documentation. + +NB: +- The total energy displayed in 'prefix.out' includes the potentiostat + contribution (-mu*N). +- calculation must be 'relax'. +- assume_isolated = 'esm' and esm_bc = 'bc2' or 'bc3' must be set + in SYSTEM namelist. + + + + .FALSE. + + zgate, relaxz, block, block_1, block_2, block_height + + +In the case of charged cells (tot_charge .ne. 0) setting gate = .TRUE. +represents the counter charge (i.e. -tot_charge) not by a homogenous +background charge but with a charged plate, which is placed at zgate +(see below). Details of the gate potential can be found in +T. Brumme, M. Calandra, F. Mauri; PRB 89, 245406 (2014). +Note, that in systems which are not symmetric with respect to the plate, +one needs to enable the dipole correction! (dipfield=.true.). +Currently, symmetry can be used with gate=.true. but carefully check +that no symmetry is included which maps z to -z even if in principle one +could still use them for symmetric systems (i.e. no dipole correction). +For nosym=.false. verbosity is set to 'high'. +Note: this option was called "monopole" in v6.0 and 6.1 of pw.x + + + + + + REQUIRED + + + Bravais-lattice index. If ibrav /= 0, specify EITHER + [ celldm(1)-celldm(6) ] OR [ A, B, C, cosAB, cosAC, cosBC ] + but NOT both. The lattice parameter "alat" is set to + alat = celldm(1) (in a.u.) or alat = A (in Angstrom); + see below for the other parameters. + For ibrav=0 specify the lattice vectors in CELL_PARAMETERS, + optionally the lattice parameter alat = celldm(1) (in a.u.) + or = A (in Angstrom), or else it is taken from CELL_PARAMETERS + +ibrav structure celldm(2)-celldm(6) + or: b,c,cosbc,cosac,cosab + 0 free + crystal axis provided in input: see card CELL_PARAMETERS + + 1 cubic P (sc) + v1 = a(1,0,0), v2 = a(0,1,0), v3 = a(0,0,1) + + 2 cubic F (fcc) + v1 = (a/2)(-1,0,1), v2 = (a/2)(0,1,1), v3 = (a/2)(-1,1,0) + + 3 cubic I (bcc) + v1 = (a/2)(1,1,1), v2 = (a/2)(-1,1,1), v3 = (a/2)(-1,-1,1) + -3 cubic I (bcc), more symmetric axis: + v1 = (a/2)(-1,1,1), v2 = (a/2)(1,-1,1), v3 = (a/2)(1,1,-1) + + 4 Hexagonal and Trigonal P celldm(3)=c/a + v1 = a(1,0,0), v2 = a(-1/2,sqrt(3)/2,0), v3 = a(0,0,c/a) + + 5 Trigonal R, 3fold axis c celldm(4)=cos(gamma) + The crystallographic vectors form a three-fold star around + the z-axis, the primitive cell is a simple rhombohedron: + v1 = a(tx,-ty,tz), v2 = a(0,2ty,tz), v3 = a(-tx,-ty,tz) + where c=cos(gamma) is the cosine of the angle gamma between + any pair of crystallographic vectors, tx, ty, tz are: + tx=sqrt((1-c)/2), ty=sqrt((1-c)/6), tz=sqrt((1+2c)/3) + -5 Trigonal R, 3fold axis <111> celldm(4)=cos(gamma) + The crystallographic vectors form a three-fold star around + <111>. Defining a' = a/sqrt(3) : + v1 = a' (u,v,v), v2 = a' (v,u,v), v3 = a' (v,v,u) + where u and v are defined as + u = tz - 2*sqrt(2)*ty, v = tz + sqrt(2)*ty + and tx, ty, tz as for case ibrav=5 + Note: if you prefer x,y,z as axis in the cubic limit, + set u = tz + 2*sqrt(2)*ty, v = tz - sqrt(2)*ty + See also the note in Modules/latgen.f90 + + 6 Tetragonal P (st) celldm(3)=c/a + v1 = a(1,0,0), v2 = a(0,1,0), v3 = a(0,0,c/a) + + 7 Tetragonal I (bct) celldm(3)=c/a + v1=(a/2)(1,-1,c/a), v2=(a/2)(1,1,c/a), v3=(a/2)(-1,-1,c/a) + + 8 Orthorhombic P celldm(2)=b/a + celldm(3)=c/a + v1 = (a,0,0), v2 = (0,b,0), v3 = (0,0,c) + + 9 Orthorhombic base-centered(bco) celldm(2)=b/a + celldm(3)=c/a + v1 = (a/2, b/2,0), v2 = (-a/2,b/2,0), v3 = (0,0,c) + -9 as 9, alternate description + v1 = (a/2,-b/2,0), v2 = (a/2, b/2,0), v3 = (0,0,c) + + 10 Orthorhombic face-centered celldm(2)=b/a + celldm(3)=c/a + v1 = (a/2,0,c/2), v2 = (a/2,b/2,0), v3 = (0,b/2,c/2) + + 11 Orthorhombic body-centered celldm(2)=b/a + celldm(3)=c/a + v1=(a/2,b/2,c/2), v2=(-a/2,b/2,c/2), v3=(-a/2,-b/2,c/2) + + 12 Monoclinic P, unique axis c celldm(2)=b/a + celldm(3)=c/a, + celldm(4)=cos(ab) + v1=(a,0,0), v2=(b*cos(gamma),b*sin(gamma),0), v3 = (0,0,c) + where gamma is the angle between axis a and b. +-12 Monoclinic P, unique axis b celldm(2)=b/a + celldm(3)=c/a, + celldm(5)=cos(ac) + v1 = (a,0,0), v2 = (0,b,0), v3 = (c*cos(beta),0,c*sin(beta)) + where beta is the angle between axis a and c + + 13 Monoclinic base-centered celldm(2)=b/a + celldm(3)=c/a, + celldm(4)=cos(ab) + v1 = ( a/2, 0, -c/2), + v2 = (b*cos(gamma), b*sin(gamma), 0), + v3 = ( a/2, 0, c/2), + where gamma is the angle between axis a and b + + 14 Triclinic celldm(2)= b/a, + celldm(3)= c/a, + celldm(4)= cos(bc), + celldm(5)= cos(ac), + celldm(6)= cos(ab) + v1 = (a, 0, 0), + v2 = (b*cos(gamma), b*sin(gamma), 0) + v3 = (c*cos(beta), c*(cos(alpha)-cos(beta)cos(gamma))/sin(gamma), + c*sqrt( 1 + 2*cos(alpha)cos(beta)cos(gamma) + - cos(alpha)^2-cos(beta)^2-cos(gamma)^2 )/sin(gamma) ) + where alpha is the angle between axis b and c + beta is the angle between axis a and c + gamma is the angle between axis a and b + + + + + + ibrav + + +Crystallographic constants - see the ibrav variable. +Specify either these OR A,B,C,cosAB,cosBC,cosAC NOT both. +Only needed values (depending on "ibrav") must be specified +alat = celldm(1) is the lattice parameter "a" (in BOHR) +If ibrav==0, only celldm(1) is used if present; +cell vectors are read from card CELL_PARAMETERS + + + + + + + + + + + + + + + + + ibrav + + +Traditional crystallographic constants: + + a,b,c in ANGSTROM + cosAB = cosine of the angle between axis a and b (gamma) + cosAC = cosine of the angle between axis a and c (beta) + cosBC = cosine of the angle between axis b and c (alpha) + +The axis are chosen according to the value of ibrav. +Specify either these OR celldm but NOT both. +Only needed values (depending on ibrav) must be specified. + +The lattice parameter alat = A (in ANGSTROM ). + +If ibrav == 0, only A is used if present, and +cell vectors are read from card CELL_PARAMETERS. + + + + + REQUIRED + + +number of atoms in the unit cell (ALL atoms, except if +space_group is set, in which case, INEQUIVALENT atoms) + + + + REQUIRED + + +number of types of atoms in the unit cell + + + + +for an insulator, nbnd = number of valence bands +(nbnd = # of electrons /2); +
for a metal, 20% more (minimum 4 more) + + +Number of electronic states (bands) to be calculated. +Note that in spin-polarized calculations the number of +k-point, not the number of bands per k-point, is doubled + + + + 0.0 + + +Total charge of the system. Useful for simulations with charged cells. +By default the unit cell is assumed to be neutral (tot_charge=0). +tot_charge=+1 means one electron missing from the system, +tot_charge=-1 means one additional electron, and so on. + +In a periodic calculation a compensating jellium background is +inserted to remove divergences if the cell is not neutral. + + + + 0.0 + + +starting charge on atomic type 'i', +to create starting potential with startingpot = 'atomic'. + + + + -1 [unspecified] + + +Total majority spin charge - minority spin charge. +Used to impose a specific total electronic magnetization. +If unspecified then tot_magnetization variable is ignored and +the amount of electronic magnetization is determined during +the self-consistent cycle. + + + + +Starting spin polarization on atomic type 'i' in a spin +polarized calculation. Values range between -1 (all spins +down for the valence electrons of atom type 'i') to 1 +(all spins up). Breaks the symmetry and provides a starting +point for self-consistency. The default value is zero, BUT a +value MUST be specified for AT LEAST one atomic type in spin +polarized calculations, unless you constrain the magnetization +(see tot_magnetization and constrained_magnetization). +Note that if you start from zero initial magnetization, you +will invariably end up in a nonmagnetic (zero magnetization) +state. If you want to start from an antiferromagnetic state, +you may need to define two different atomic species +corresponding to sublattices of the same atomic type. +starting_magnetization is ignored if you are performing a +non-scf calculation, if you are restarting from a previous +run, or restarting from an interrupted run. +If you fix the magnetization with tot_magnetization, +you should not specify starting_magnetization. +In the spin-orbit case starting with zero +starting_magnetization on all atoms imposes time reversal +symmetry. The magnetization is never calculated and +kept zero (the internal variable domag is .FALSE.). + + + + REQUIRED + + +kinetic energy cutoff (Ry) for wavefunctions + + + + 4 * ecutwfc + + +Kinetic energy cutoff (Ry) for charge density and potential +For norm-conserving pseudopotential you should stick to the +default value, you can reduce it by a little but it will +introduce noise especially on forces and stress. +If there are ultrasoft PP, a larger value than the default is +often desirable (ecutrho = 8 to 12 times ecutwfc, typically). +PAW datasets can often be used at 4*ecutwfc, but it depends +on the shape of augmentation charge: testing is mandatory. +The use of gradient-corrected functional, especially in cells +with vacuum, or for pseudopotential without non-linear core +correction, usually requires an higher values of ecutrho +to be accurately converged. + + + + ecutrho + + +Kinetic energy cutoff (Ry) for the exact exchange operator in +EXX type calculations. By default this is the same as ecutrho +but in some EXX calculations significant speed-up can be found +by reducing ecutfock, at the expense of some loss in accuracy. +Must be .gt. ecutwfc. Not implemented for stress calculation. +Use with care, especially in metals where it may give raise +to instabilities. + + + + + + + + + + +Three-dimensional FFT mesh (hard grid) for charge +density (and scf potential). If not specified +the grid is calculated based on the cutoff for +charge density (see also ecutrho) +Note: you must specify all three dimensions for this setting to +be used. + + + + + + + + + + +Three-dimensional mesh for wavefunction FFT and for the smooth +part of charge density ( smooth grid ). +Coincides with nr1, nr2, nr3 if ecutrho = 4 * ecutwfc ( default ) +Note: you must specify all three dimensions for this setting to +be used. + + + + .FALSE. + + +if (.TRUE.) symmetry is not used. Consequences: + +- if a list of k points is provided in input, it is used + "as is": symmetry-inequivalent k-points are not generated, + and the charge density is not symmetrized; + +- if a uniform (Monkhorst-Pack) k-point grid is provided in + input, it is expanded to cover the entire Brillouin Zone, + irrespective of the crystal symmetry. + Time reversal symmetry is assumed so k and -k are considered + as equivalent unless noinv=.true. is specified. + +Do not use this option unless you know exactly what you want +and what you get. May be useful in the following cases: +- in low-symmetry large cells, if you cannot afford a k-point + grid with the correct symmetry +- in MD simulations +- in calculations for isolated atoms + + + + .FALSE. + + +if (.TRUE.) symmetry is not used, and k points are +forced to have the symmetry of the Bravais lattice; +an automatically generated Monkhorst-Pack grid will contain +all points of the grid over the entire Brillouin Zone, +plus the points rotated by the symmetries of the Bravais +lattice which were not in the original grid. The same +applies if a k-point list is provided in input instead +of a Monkhorst-Pack grid. Time reversal symmetry is assumed +so k and -k are equivalent unless noinv=.true. is specified. +This option differs from nosym because it forces k-points +in all cases to have the full symmetry of the Bravais lattice +(not all uniform grids have such property!) + + + + .FALSE. + + +if (.TRUE.) disable the usage of k => -k symmetry +(time reversal) in k-point generation + + + + .FALSE. + + +if (.TRUE.) disable the usage of magnetic symmetry operations +that consist in a rotation + time reversal. + + + + .FALSE. + + +if (.TRUE.) force the symmetry group to be symmorphic by disabling +symmetry operations having an associated fractionary translation + + + + .FALSE. + + +if (.TRUE.) do not discard symmetry operations with an +associated fractionary translation that does not send the +real-space FFT grid into itself. These operations are +incompatible with real-space symmetrization but not with the +new G-space symmetrization. BEWARE: do not use for phonons +and for hybrid functionals! Both still use symmetrization +in real space. + + + + + Available options are: + + +gaussian smearing for metals; +see variables smearing and degauss + + +Tetrahedron method, Bloechl's version: +P.E. Bloechl, PRB 49, 16223 (1994) +Requires uniform grid of k-points, to be +automatically generated (see card K_POINTS). +Well suited for calculation of DOS, +less so (because not variational) for +force/optimization/dynamics calculations. + + +Original linear tetrahedron method. +To be used only as a reference; +the optimized tetrahedron method is more efficient. + + +Optimized tetrahedron method: +see M. Kawamura, PRB 89, 094515 (2014). +Can be used for phonon calculations as well. + + +for insulators with a gap + + +The occupation are read from input file, +card OCCUPATIONS. Option valid only for a +single k-point, requires nbnd to be set +in input. Occupations should be consistent +with the value of tot_charge. + + + + + .FALSE. + + +This flag is used for isolated atoms (nat=1) together with +occupations='from_input'. If it is .TRUE., the wavefunctions +are ordered as the atomic starting wavefunctions, independently +from their eigenvalue. The occupations indicate which atomic +states are filled. + +The order of the states is written inside the UPF pseudopotential file. +In the scalar relativistic case: +S -> l=0, m=0 +P -> l=1, z, x, y +D -> l=2, r^2-3z^2, xz, yz, xy, x^2-y^2 + +In the noncollinear magnetic case (with or without spin-orbit), +each group of states is doubled. For instance: +P -> l=1, z, x, y for spin up, l=1, z, x, y for spin down. +Up and down is relative to the direction of the starting +magnetization. + +In the case with spin-orbit and time-reversal +(starting_magnetization=0.0) the atomic wavefunctions are +radial functions multiplied by spin-angle functions. +For instance: +P -> l=1, j=1/2, m_j=-1/2,1/2. l=1, j=3/2, + m_j=-3/2, -1/2, 1/2, 3/2. + +In the magnetic case with spin-orbit the atomic wavefunctions +can be forced to be spin-angle functions by setting +starting_spin_angle to .TRUE.. + + + + .FALSE. + + +In the spin-orbit case when domag=.TRUE., by default, +the starting wavefunctions are initialized as in scalar +relativistic noncollinear case without spin-orbit. + +By setting starting_spin_angle=.TRUE. this behaviour can +be changed and the initial wavefunctions are radial +functions multiplied by spin-angle functions. + +When domag=.FALSE. the initial wavefunctions are always +radial functions multiplied by spin-angle functions +independently from this flag. + +When lspinorb is .FALSE. this flag is not used. + + + + 0.D0 Ry + + +value of the gaussian spreading (Ry) for brillouin-zone +integration in metals. + + + + 'gaussian' + + + +Available options are: + + +ordinary Gaussian spreading (Default) + + +Methfessel-Paxton first-order spreading +(see PRB 40, 3616 (1989)). + + +Marzari-Vanderbilt cold smearing +(see PRL 82, 3296 (1999)) + + +smearing with Fermi-Dirac function + + + + + 1 + + +nspin = 1 : non-polarized calculation (default) + +nspin = 2 : spin-polarized calculation, LSDA + (magnetization along z axis) + +nspin = 4 : spin-polarized calculation, noncollinear + (magnetization in generic direction) + DO NOT specify nspin in this case; + specify noncolin=.TRUE. instead + + + + .false. + + +if .true. the program will perform a noncollinear calculation. + + + + 0.0 + + q2sigma + + + + 0.0 + + q2sigma + + + + 0.1 + + +ecfixed, qcutz, q2sigma: parameters for modified functional to be +used in variable-cell molecular dynamics (or in stress calculation). +"ecfixed" is the value (in Rydberg) of the constant-cutoff; +"qcutz" and "q2sigma" are the height and the width (in Rydberg) +of the energy step for reciprocal vectors whose square modulus +is greater than "ecfixed". In the kinetic energy, G^2 is +replaced by G^2 + qcutz * (1 + erf ( (G^2 - ecfixed)/q2sigma) ) +See: M. Bernasconi et al, J. Phys. Chem. Solids 56, 501 (1995), +doi:10.1016/0022-3697(94)00228-2 + + + + read from pseudopotential files + + +Exchange-correlation functional: eg 'PBE', 'BLYP' etc +See Modules/funct.f90 for allowed values. +Overrides the value read from pseudopotential files. +Use with care and if you know what you are doing! + + + + it depends on the specified functional + + +Fraction of EXX for hybrid functional calculations. In the case of +input_dft='PBE0', the default value is 0.25, while for input_dft='B3LYP' +the exx_fraction default value is 0.20. + + + + 0.106 + + +screening_parameter for HSE like hybrid functionals. +For more information, see: +J. Chem. Phys. 118, 8207 (2003), doi:10.1063/1.1564060 +J. Chem. Phys. 124, 219906 (2006), doi:10.1063/1.2204597 + + + + 'gygi-baldereschi' + + + +Specific for EXX. It selects the kind of approach to be used +for treating the Coulomb potential divergencies at small q vectors. + + appropriate for cubic and quasi-cubic supercells + + appropriate for cubic and quasi-cubic supercells + + appropriate for strongly anisotropic supercells, see also ecutvcut. + + sets Coulomb potential at G,q=0 to 0.0 (required for GAU-PBE) + + + + + .true. + + +Specific for EXX. If .true., extrapolate the G=0 term of the +potential (see README in examples/EXX_example for more) +Set this to .false. for GAU-PBE. + + + + 0.0 Ry + + exxdiv_treatment + + +Reciprocal space cutoff for correcting Coulomb potential +divergencies at small q vectors. + + + + + + + + + + +Three-dimensional mesh for q (k1-k2) sampling of +the Fock operator (EXX). Can be smaller than +the number of k-points. + +Currently this defaults to the size of the k-point mesh used. +In QE =< 5.0.2 it defaulted to nqx1=nqx2=nqx3=1. + + + + .FALSE. + + +DFT+U (formerly known as LDA+U) currently works only for +a few selected elements. Modify Modules/set_hubbard_l.f90 and +PW/src/tabd.f90 if you plan to use DFT+U with an element that +is not configured there. + + +Specify lda_plus_u = .TRUE. to enable DFT+U calculations +See: Anisimov, Zaanen, and Andersen, PRB 44, 943 (1991); + Anisimov et al., PRB 48, 16929 (1993); + Liechtenstein, Anisimov, and Zaanen, PRB 52, R5467 (1994). +You must specify, for each species with a U term, the value of +U and (optionally) alpha, J of the Hubbard model (all in eV): +see lda_plus_u_kind, Hubbard_U, Hubbard_alpha, Hubbard_J + + + + 0 + + +Specifies the type of DFT+U calculation: + + 0 simplified version of Cococcioni and de Gironcoli, + PRB 71, 035105 (2005), using Hubbard_U + + 1 rotationally invariant scheme of Liechtenstein et al., + using Hubbard_U and Hubbard_J + + + + 0.D0 for all species + + +Hubbard_U(i): U parameter (eV) for species i, DFT+U calculation + + + + 0.D0 for all species + + +Hubbard_J0(i): J0 parameter (eV) for species i, DFT+U+J calculation, +see PRB 84, 115108 (2011) for details. + + + + 0.D0 for all species + + +Hubbard_alpha(i) is the perturbation (on atom i, in eV) +used to compute U with the linear-response method of +Cococcioni and de Gironcoli, PRB 71, 35105 (2005) +(only for lda_plus_u_kind=0) + + + + 0.D0 for all species + + +Hubbard_beta(i) is the perturbation (on atom i, in eV) +used to compute J0 with the linear-response method of +Cococcioni and de Gironcoli, PRB 71, 35105 (2005) +(only for lda_plus_u_kind=0). See also +PRB 84, 115108 (2011). + + + + 0.D0 for all species + + +Hubbard_J(i,ityp): J parameters (eV) for species ityp, +used in DFT+U calculations (only for lda_plus_u_kind=1) +For p orbitals: J = Hubbard_J(1,ityp); +For d orbitals: J = Hubbard_J(1,ityp), B = Hubbard_J(2,ityp); +For f orbitals: J = Hubbard_J(1,ityp), E2 = Hubbard_J(2,ityp), + E3= Hubbard_J(3,ityp). +If B or E2 or E3 are not specified or set to 0 they will be +calculated from J using atomic ratios. + + + + -1.d0 that means NOT SET + + +In the first iteration of an DFT+U run it overwrites +the m-th eigenvalue of the ns occupation matrix for the +ispin component of atomic species I. Leave unchanged +eigenvalues that are not set. This is useful to suggest +the desired orbital occupations when the default choice +takes another path. + + + + 'atomic' + + + +Only active when lda_plus_U is .true., specifies the type +of projector on localized orbital to be used in the DFT+U +scheme. + +Currently available choices: + + use atomic wfc's (as they are) to build the projector + + use Lowdin orthogonalized atomic wfc's + + +Lowdin normalization of atomic wfc. Keep in mind: +atomic wfc are not orthogonalized in this case. +This is a "quick and dirty" trick to be used when +atomic wfc from the pseudopotential are not +normalized (and thus produce occupation whose +value exceeds unity). If orthogonalized wfc are +not needed always try 'atomic' first. + + +use the information from file "prefix".atwfc that must +have been generated previously, for instance by pmw.x +(see PP/src/poormanwannier.f90 for details). + + +use the pseudopotential projectors. The charge density +outside the atomic core radii is excluded. +N.B.: for atoms with +U, a pseudopotential with the +all-electron atomic wavefunctions is required (i.e., +as generated by ld1.x with lsave_wfc flag). + + +NB: forces and stress currently implemented only for the +'atomic' and 'pseudo' choice. + + + + + +The direction of the electric field or dipole correction is +parallel to the bg(:,edir) reciprocal lattice vector, so the +potential is constant in planes defined by FFT grid points; +edir = 1, 2 or 3. Used only if tefield is .TRUE. + + + + 0.5D0 + + +Position of the maximum of the saw-like potential along crystal +axis edir, within the unit cell (see below), 0 < emaxpos < 1 +Used only if tefield is .TRUE. + + + + 0.1D0 + + +Zone in the unit cell where the saw-like potential decreases. +( see below, 0 < eopreg < 1 ). Used only if tefield is .TRUE. + + + + 0.001 a.u. + + +Amplitude of the electric field, in ***Hartree*** a.u.; +1 a.u. = 51.4220632*10^10 V/m. Used only if tefield==.TRUE. +The saw-like potential increases with slope eamp in the +region from (emaxpos+eopreg-1) to (emaxpos), then decreases +to 0 until (emaxpos+eopreg), in units of the crystal +vector edir. Important: the change of slope of this +potential must be located in the empty region, or else +unphysical forces will result. + + + + +The angle expressed in degrees between the initial +magnetization and the z-axis. For noncollinear calculations +only; index i runs over the atom types. + + + + +The angle expressed in degrees between the projection +of the initial magnetization on x-y plane and the x-axis. +For noncollinear calculations only. + + + + lambda, fixed_magnetization + + 'none' + + + +Used to perform constrained calculations in magnetic systems. +Currently available choices: + + +no constraint + + +total magnetization is constrained by +adding a penalty functional to the total energy: + +LAMBDA * SUM_{i} ( magnetization(i) - fixed_magnetization(i) )**2 + +where the sum over i runs over the three components of +the magnetization. Lambda is a real number (see below). +Noncolinear case only. Use tot_magnetization for LSDA + + +atomic magnetization are constrained to the defined +starting magnetization adding a penalty: + +LAMBDA * SUM_{i,itype} ( magnetic_moment(i,itype) - mcons(i,itype) )**2 + +where i runs over the cartesian components (or just z +in the collinear case) and itype over the types (1-ntype). +mcons(:,:) array is defined from starting_magnetization, +(and angle1, angle2 in the non-collinear case). lambda is +a real number + + +the angle theta of the total magnetization +with the z axis (theta = fixed_magnetization(3)) +is constrained: + +LAMBDA * ( arccos(magnetization(3)/mag_tot) - theta )**2 + +where mag_tot is the modulus of the total magnetization. + + +not all the components of the atomic +magnetic moment are constrained but only the cosine +of angle1, and the penalty functional is: + +LAMBDA * SUM_{itype} ( mag_mom(3,itype)/mag_mom_tot - cos(angle1(ityp)) )**2 + + +N.B.: symmetrization may prevent to reach the desired orientation +of the magnetization. Try not to start with very highly symmetric +configurations or use the nosym flag (only as a last remedy) + + + + + constrained_magnetization + + 0.d0 + + +total magnetization vector (x,y,z components) to be kept +fixed when constrained_magnetization=='total' + + + + constrained_magnetization + + 1.d0 + + +parameter used for constrained_magnetization calculations +N.B.: if the scf calculation does not converge, try to reduce lambda + to obtain convergence, then restart the run with a larger lambda + + + + 100 + + +Number of iterations after which the program +writes all the atomic magnetic moments. + + + + +if .TRUE. the noncollinear code can use a pseudopotential with +spin-orbit. + + + + 'none' + + + +Used to perform calculation assuming the system to be +isolated (a molecule or a cluster in a 3D supercell). + +Currently available choices: + + +(default): regular periodic calculation w/o any correction. + + +the Makov-Payne correction to the +total energy is computed. An estimate of the vacuum +level is also calculated so that eigenvalues can be +properly aligned. ONLY FOR CUBIC SYSTEMS (ibrav=1,2,3). +Theory: G.Makov, and M.C.Payne, + "Periodic boundary conditions in ab initio + calculations" , PRB 51, 4014 (1995). + + +Martyna-Tuckerman correction +to both total energy and scf potential. Adapted from: +G.J. Martyna, and M.E. Tuckerman, +"A reciprocal space based method for treating long +range interactions in ab-initio and force-field-based +calculation in clusters", J. Chem. Phys. 110, 2810 (1999), +doi:10.1063/1.477923. + + +Effective Screening Medium Method. +For polarized or charged slab calculation, embeds +the simulation cell within an effective semi- +infinite medium in the perpendicular direction +(along z). Embedding regions can be vacuum or +semi-infinite metal electrodes (use esm_bc to +choose boundary conditions). If between two +electrodes, an optional electric field +('esm_efield') may be applied. Method described in +M. Otani and O. Sugino, "First-principles calculations +of charged surfaces and interfaces: A plane-wave +nonrepeated slab approach", PRB 73, 115407 (2006). + +NB: + - Two dimensional (xy plane) average charge density + and electrostatic potentials are printed out to + 'prefix.esm1'. + + - Requires cell with a_3 lattice vector along z, + normal to the xy plane, with the slab centered + around z=0. Also requires symmetry checking to be + disabled along z, either by setting nosym = .TRUE. + or by very slight displacement (i.e., 5e-4 a.u.) + of the slab along z. + + - Components of the total stress; sigma_xy, sigma_yz, + sigma_zz, sigma_zy, and sigma_zx are meaningless + bacause ESM stress routines calculate only + components of stress; sigma_xx, sigma_xy, sigma_yx, + and sigma_yy. + + - In case of calculation='vc-relax', use + cell_dofree='2Dxy' or other parameters so that + c-vector along z-axis should not be moved. + +See esm_bc, esm_efield, esm_w, esm_nfit. + + + + + assume_isolated + + 'pbc' + + + +If assume_isolated = 'esm', determines the boundary +conditions used for either side of the slab. + +Currently available choices: + + (default): regular periodic calculation (no ESM). + + Vacuum-slab-vacuum (open boundary conditions). + + +Metal-slab-metal (dual electrode configuration). +See also esm_efield. + + Vacuum-slab-metal + + + + + assume_isolated + + 0.d0 + + +If assume_isolated = 'esm', determines the position offset +[in a.u.] of the start of the effective screening region, +measured relative to the cell edge. (ESM region begins at +z = +/- [L_z/2 + esm_w] ). + + + + assume_isolated + + 0.d0 + + +If assume_isolated = 'esm' and esm_bc = 'bc2', gives the +magnitude of the electric field [Ry/a.u.] to be applied +between semi-infinite ESM electrodes. + + + + assume_isolated + + 4 + + +If assume_isolated = 'esm', gives the number of z-grid points +for the polynomial fit along the cell edge. + + + + lfcpopt + + 0.d0 + + +If lfcpopt = .TRUE., gives the target Fermi energy [Ry]. One can start +with appropriate total charge of the system by giving 'tot_charge'. + + + + 'none' + + +london_s6, london_rcut, london_c6, london_rvdw, ts_vdw_econv_thr, ts_vdw_isolated, xdm_a1, xdm_a2 + + + +Type of Van der Waals correction. Allowed values: + + +Semiempirical Grimme's DFT-D2. +Optional variables: london_s6, london_rcut, london_c6, london_rvdw, +S. Grimme, J. Comp. Chem. 27, 1787 (2006), doi:10.1002/jcc.20495 +V. Barone et al., J. Comp. Chem. 30, 934 (2009), doi:10.1002/jcc.21112 + + +Tkatchenko-Scheffler dispersion corrections with first-principle derived +C6 coefficients (implemented in CP only). +Optional variables: ts_vdw_econv_thr, ts_vdw_isolated +See A. Tkatchenko and M. Scheffler, PRL 102, 073005 (2009). + + +Exchange-hole dipole-moment model. Optional variables: xdm_a1, xdm_a2 +A. D. Becke et al., J. Chem. Phys. 127, 154108 (2007), doi:10.1063/1.2795701 +A. Otero de la Roza et al., J. Chem. Phys. 136, 174109 (2012), +doi:10.1063/1.4705760 + + Note that non-local functionals (eg vdw-DF) are NOT specified here but in input_dft + + + + + .FALSE. + + +OBSOLESCENT, same as vdw_corr='DFT-D' + + + + 0.75 + + +global scaling parameter for DFT-D. Default is good for PBE. + + + + standard Grimme-D2 values + + +atomic C6 coefficient of each atom type + +( if not specified default values from S. Grimme, J. Comp. Chem. 27, 1787 (2006), + doi:10.1002/jcc.20495 are used; see file Modules/mm_dispersion.f90 ) + + + + standard Grimme-D2 values + + +atomic vdw radii of each atom type + +( if not specified default values from S. Grimme, J. Comp. Chem. 27, 1787 (2006), + doi:10.1002/jcc.20495 are used; see file Modules/mm_dispersion.f90 ) + + + + 200 + + +cutoff radius (a.u.) for dispersion interactions + + + + 1.D-6 + + +Optional: controls the convergence of the vdW energy (and forces). The default value +is a safe choice, likely too safe, but you do not gain much in increasing it + + + + .FALSE. + + +Optional: set it to .TRUE. when computing the Tkatchenko-Scheffler vdW energy +for an isolated (non-periodic) system. + + + + .FALSE. + + +OBSOLESCENT, same as vdw_corr='xdm' + + + + 0.6836 + + +Damping function parameter a1 (adimensional). This value should change +with the exchange-correlation functional. The default corresponds to +PW86PBE. +For other functionals, see: + http://schooner.chem.dal.ca/wiki/XDM + A. Otero de la Roza, E. R. Johnson, J. Chem. Phys. 138, 204109 (2013), + doi:10.1063/1.4705760 + + + + 1.5045 + + +Damping function parameter a2 (angstrom). This value should change +with the exchange-correlation functional. The default corresponds to +PW86PBE. +For other functionals, see: + http://schooner.chem.dal.ca/wiki/XDM + A. Otero de la Roza, E. R. Johnson, J. Chem. Phys. 138, 204109 (2013), + doi:10.1063/1.4705760 + + + + 0 + + +The number of the space group of the crystal, as given +in the International Tables of Crystallography A (ITA). +This allows to give in input only the inequivalent atomic +positions. The positions of all the symmetry equivalent atoms +are calculated by the code. Used only when the atomic positions +are of type crystal_sg. + + + + .FALSE. + + +Used only for monoclinic lattices. If .TRUE. the b +unique ibrav (-12 or -13) are used, and symmetry +equivalent positions are chosen assuming that the +two fold axis or the mirror normal is parallel to the +b axis. If .FALSE. it is parallel to the c axis. + + + + 1 + + +Used only for space groups that in the ITA allow +the use of two different origins. origin_choice=1, +means the first origin, while origin_choice=2 is the +second origin. + + + + .TRUE. + + +Used only for rhombohedral space groups. +When .TRUE. the coordinates of the inequivalent atoms are +given with respect to the rhombohedral axes, when .FALSE. +the coordinates of the inequivalent atoms are given with +respect to the hexagonal axes. They are converted internally +to the rhombohedral axes and ibrav=5 is used in both cases. + + + + + + 0.5 + + +used only if gate = .TRUE. +Specifies the position of the charged plate which represents +the counter charge in doped systems (tot_charge .ne. 0). +In units of the unit cell length in z direction, zgate in ]0,1[ +Details of the gate potential can be found in +T. Brumme, M. Calandra, F. Mauri; PRB 89, 245406 (2014). + + + + .FALSE. + + +used only if gate = .TRUE. +Allows the relaxation of the system towards the charged plate. +Use carefully and utilize either a layer of fixed atoms or a +potential barrier (block=.TRUE.) to avoid the atoms moving to +the position of the plate or the dipole of the dipole +correction (dipfield=.TRUE.). + + + + .FALSE. + + +used only if gate = .TRUE. +Adds a potential barrier to the total potential seen by the +electrons to mimic a dielectric in field effect configuration +and/or to avoid electrons spilling into the vacuum region for +electron doping. Potential barrier is from block_1 to block_2 and +has a height of block_height. +If dipfield = .TRUE. then eopreg is used for a smooth increase and +decrease of the potential barrier. + + + + 0.45 + + +used only if gate = .TRUE. and block = .TRUE. +lower beginning of the potential barrier, in units of the +unit cell size along z, block_1 in ]0,1[ + + + + 0.55 + + +used only if gate = .TRUE. and block = .TRUE. +upper beginning of the potential barrier, in units of the +unit cell size along z, block_2 in ]0,1[ + + + + 0.1 + + +used only if gate = .TRUE. and block = .TRUE. +Height of the potential barrier in Rydberg. + + + + + + + 100 + + +maximum number of iterations in a scf step + + + + .TRUE. + + +If .false. do not stop molecular dynamics or ionic relaxation +when electron_maxstep is reached. Use with care. + + + + 1.D-6 + + +Convergence threshold for selfconsistency: + estimated energy error < conv_thr +(note that conv_thr is extensive, like the total energy). + +For non-self-consistent calculations, conv_thr is used +to set the default value of the threshold (ethr) for +iterative diagonalizazion: see diago_thr_init + + + + .FALSE + + +If .TRUE. this turns on the use of an adaptive conv_thr for +the inner scf loops when using EXX. + + + + 1.D-3 + + +When adaptive_thr = .TRUE. this is the convergence threshold +used for the first scf cycle. + + + + 1.D-1 + + +When adaptive_thr = .TRUE. the convergence threshold for +each scf cycle is given by: +max( conv_thr, conv_thr_multi * dexx ) + + + + 'plain' + + + Available options are: + + charge density Broyden mixing + + +as above, with simple Thomas-Fermi screening +(for highly homogeneous systems) + + +as above, with local-density-dependent TF screening +(for highly inhomogeneous systems) + + + + + 0.7D0 + + +mixing factor for self-consistency + + + + 8 + + +number of iterations used in mixing scheme. +If you are tight with memory, you may reduce it to 4 or so. + + + + 0 + + +For DFT+U : number of iterations with fixed ns ( ns is the +atomic density appearing in the Hubbard term ). + + + + 'david' + + + Available options are: + + +Davidson iterative diagonalization with overlap matrix +(default). Fast, may in some rare cases fail. + + +Conjugate-gradient-like band-by-band diagonalization. +Slower than 'david' but uses less memory and is +(a little bit) more robust. + + +OBSOLETE, use -ndiag 1 instead. +The subspace diagonalization in Davidson is performed +by a fully distributed-memory parallel algorithm on +4 or more processors, by default. The allocated memory +scales down with the number of procs. Procs involved +in diagonalization can be changed with command-line +option -ndiag N. On multicore CPUs it is often +convenient to let just one core per CPU to work +on linear algebra. + + + + + 0 + + OBSOLETE: use command-line option "-ndiag XX" instead + + + + +Convergence threshold (ethr) for iterative diagonalization +(the check is on eigenvalue convergence). + +For scf calculations: default is 1.D-2 if starting from a +superposition of atomic orbitals; 1.D-5 if starting from a +charge density. During self consistency the threshold +is automatically reduced (but never below 1.D-13) when +approaching convergence. + +For non-scf calculations: default is (conv_thr/N elec)/10. + + + + +For conjugate gradient diagonalization: max number of iterations + + + + 4 + + +For Davidson diagonalization: dimension of workspace +(number of wavefunction packets, at least 2 needed). +A larger value may yield a smaller number of iterations in +the algorithm but uses more memory and more CPU time in +subspace diagonalization. +Try diago_david_ndim=2 if you are tight on memory or if +the time spent in subspace diagonalization (cdiaghg/rdiaghg) +is significant compared to the time spent in h_psi + + + + .FALSE. + + +If .TRUE. all the empty states are diagonalized at the same level +of accuracy of the occupied ones. Otherwise the empty states are +diagonalized using a larger threshold (this should not affect +total energy, forces, and other ground-state properties). + + + + 0.D0 + + +Amplitude of the finite electric field (in Ry a.u.; +1 a.u. = 36.3609*10^10 V/m). Used only if lelfield==.TRUE. +and if k-points (K_POINTS card) are not automatic. + + + + (0.D0, 0.D0, 0.D0) + + +Finite electric field (in Ry a.u.=36.3609*10^10 V/m) in +cartesian axis. Used only if lelfield==.TRUE. and if +k-points (K_POINTS card) are automatic. + + + + 'none' + + + Available options are: + + +set the zero of the electronic polarization (with lelfield==.true..) +to the result of a previous calculation + + +write on disk data on electronic polarization to be read in another +calculation + + +none of the above points + + + + + + Available options are: + + +starting potential from atomic charge superposition +(default for scf, *relax, *md) + + +start from existing "charge-density.xml" file in the +directory specified by variables prefix and outdir +For nscf and bands calculation this is the default +and the only sensible possibility. + + + + + 'atomic+random' + + + Available options are: + + +Start from superposition of atomic orbitals. +If not enough atomic orbitals are available, +fill with random numbers the remaining wfcs +The scf typically starts better with this option, +but in some high-symmetry cases one can "loose" +valence states, ending up in the wrong ground state. + + +As above, plus a superimposed "randomization" +of atomic orbitals. Prevents the "loss" of states +mentioned above. + + +Start from random wfcs. Slower start of scf but safe. +It may also reduce memory usage in conjunction with +diagonalization='cg'. + + +Start from an existing wavefunction file in the +directory specified by variables prefix and outdir. + + + + + .FALSE. + + +If .true., use the real-space algorithm for augmentation +charges in ultrasoft pseudopotentials. +Must faster execution of ultrasoft-related calculations, +but numerically less accurate than the default algorithm. +Use with care and after testing! + + + + + + + + +Specify the type of ionic dynamics. + +For different type of calculation different possibilities are +allowed and different default values apply: + +CASE ( calculation == 'relax' ) + + +(default) use BFGS quasi-newton algorithm, +based on the trust radius procedure, +for structural relaxation + + +use damped (quick-min Verlet) +dynamics for structural relaxation +Can be used for constrained +optimisation: see CONSTRAINTS card + + +CASE ( calculation == 'md' ) + + +(default) use Verlet algorithm to integrate +Newton's equation. For constrained +dynamics, see CONSTRAINTS card + + +ion dynamics is over-damped Langevin + + +over-damped Langevin with Smart Monte Carlo: +see R.J. Rossky, JCP, 69, 4628 (1978), doi:10.1063/1.436415 + + +CASE ( calculation == 'vc-relax' ) + + +(default) use BFGS quasi-newton algorithm; +cell_dynamics must be 'bfgs' too + + +use damped (Beeman) dynamics for +structural relaxation + + +CASE ( calculation == 'vc-md' ) + + +(default) use Beeman algorithm to integrate +Newton's equation + + + + + 'default' + + + Available options are: + + +if restarting, use atomic positions read from the +restart file; in all other cases, use atomic +positions from standard input. + + +restart the simulation with atomic positions read +from standard input, even if restarting. + + + + + 'atomic' + + + +Used to extrapolate the potential from preceding ionic steps. + + no extrapolation + + +extrapolate the potential as if it was a sum of +atomic-like orbitals + + +extrapolate the potential with first-order +formula + + +as above, with second order formula + + +Note: 'first_order' and 'second-order' extrapolation make sense +only for molecular dynamics calculations + + + + + 'none' + + + +Used to extrapolate the wavefunctions from preceding ionic steps. + + no extrapolation + + +extrapolate the wave-functions with first-order formula. + + +as above, with second order formula. + + +Note: 'first_order' and 'second-order' extrapolation make sense +only for molecular dynamics calculations + + + + + .FALSE. + + +This keyword is useful when simulating the dynamics and/or the +thermodynamics of an isolated system. If set to true the total +torque of the internal forces is set to zero by adding new forces +that compensate the spurious interaction with the periodic +images. This allows for the use of smaller supercells. + +BEWARE: since the potential energy is no longer consistent with +the forces (it still contains the spurious interaction with the +repeated images), the total energy is not conserved anymore. +However the dynamical and thermodynamical properties should be +in closer agreement with those of an isolated system. +Also the final energy of a structural relaxation will be higher, +but the relaxation itself should be faster. + + + + + + 'not_controlled' + + + Available options are: + + +control ionic temperature via velocity rescaling +(first method) see parameters tempw, tolp, and +nraise (for VC-MD only). This rescaling method +is the only one currently implemented in VC-MD + + +control ionic temperature via velocity rescaling +(second method) see parameters tempw and nraise + + +control ionic temperature via velocity rescaling +(third method) see parameter delta_t + + +reduce ionic temperature every nraise steps +by the (negative) value delta_t + + +control ionic temperature using "soft" velocity +rescaling - see parameters tempw and nraise + + +control ionic temperature using Andersen thermostat +see parameters tempw and nraise + + +initialize ion velocities to temperature tempw +and leave uncontrolled further on + + +(default) ionic temperature is not controlled + + + + + 300.D0 + + +Starting temperature (Kelvin) in MD runs +target temperature for most thermostats. + + + + 100.D0 + + +Tolerance for velocity rescaling. Velocities are rescaled if +the run-averaged and target temperature differ more than tolp. + + + + 1.D0 + + +if ion_temperature == 'rescale-T' : + at each step the instantaneous temperature is multiplied + by delta_t; this is done rescaling all the velocities. + +if ion_temperature == 'reduce-T' : + every 'nraise' steps the instantaneous temperature is + reduced by -delta_t (i.e. delta_t < 0 is added to T) + +The instantaneous temperature is calculated at the end of +every ionic move and BEFORE rescaling. This is the temperature +reported in the main output. + +For delta_t < 0, the actual average rate of heating or cooling +should be roughly C*delta_t/(nraise*dt) (C=1 for an +ideal gas, C=0.5 for a harmonic solid, theorem of energy +equipartition between all quadratic degrees of freedom). + + + + 1 + + +if ion_temperature == 'reduce-T' : + every nraise steps the instantaneous temperature is + reduced by -delta_t (i.e. delta_t is added to the temperature) + +if ion_temperature == 'rescale-v' : + every nraise steps the average temperature, computed from + the last nraise steps, is rescaled to tempw + +if ion_temperature == 'rescaling' and calculation == 'vc-md' : + every nraise steps the instantaneous temperature + is rescaled to tempw + +if ion_temperature == 'berendsen' : + the "rise time" parameter is given in units of the time step: + tau = nraise*dt, so dt/tau = 1/nraise + +if ion_temperature == 'andersen' : + the "collision frequency" parameter is given as nu=1/tau + defined above, so nu*dt = 1/nraise + + + + .FALSE. + + +This keyword applies only in the case of molecular dynamics or +damped dynamics. If true the ions are refolded at each step into +the supercell. + + + + + + + 100.D0 + + +Max reduction factor for conv_thr during structural optimization +conv_thr is automatically reduced when the relaxation +approaches convergence so that forces are still accurate, +but conv_thr will not be reduced to less that conv_thr / upscale. + + + + 1 + + +Number of old forces and displacements vectors used in the +PULAY mixing of the residual vectors obtained on the basis +of the inverse hessian matrix given by the BFGS algorithm. +When bfgs_ndim = 1, the standard quasi-Newton BFGS method is +used. +(bfgs only) + + + + 0.8D0 + + +Maximum ionic displacement in the structural relaxation. +(bfgs only) + + + + 1.D-3 + + +Minimum ionic displacement in the structural relaxation +BFGS is reset when trust_radius < trust_radius_min. +(bfgs only) + + + + 0.5D0 + + +Initial ionic displacement in the structural relaxation. +(bfgs only) + + + + 0.01D0 + + w_2 + + + + 0.5D0 + + +Parameters used in line search based on the Wolfe conditions. +(bfgs only) + + + + + + + + + +Specify the type of dynamics for the cell. +For different type of calculation different possibilities +are allowed and different default values apply: + +CASE ( calculation == 'vc-relax' ) + + no dynamics + + steepest descent ( not implemented ) + + +damped (Beeman) dynamics of the Parrinello-Rahman extended lagrangian + + +damped (Beeman) dynamics of the new Wentzcovitch extended lagrangian + + +BFGS quasi-newton algorithm (default) +ion_dynamics must be 'bfgs' too + + +CASE ( calculation == 'vc-md' ) + + no dynamics + + +(Beeman) molecular dynamics of the Parrinello-Rahman extended lagrangian + + +(Beeman) molecular dynamics of the new Wentzcovitch extended lagrangian + + + + + 0.D0 + + +Target pressure [KBar] in a variable-cell md or relaxation run. + + + + +0.75*Tot_Mass/pi**2 for Parrinello-Rahman MD; +0.75*Tot_Mass/pi**2/Omega**(2/3) for Wentzcovitch MD + + +Fictitious cell mass [amu] for variable-cell simulations +(both 'vc-md' and 'vc-relax') + + + + 2.0 for variable-cell calculations, 1.0 otherwise + + +Used in the construction of the pseudopotential tables. +It should exceed the maximum linear contraction of the +cell during a simulation. + + + + 0.5D0 Kbar + + +Convergence threshold on the pressure for variable cell +relaxation ('vc-relax' : note that the other convergence + thresholds for ionic relaxation apply as well). + + + + 'all' + + + +Select which of the cell parameters should be moved: + + all axis and angles are moved + + only the x component of axis 1 (v1_x) is moved + + only the y component of axis 2 (v2_y) is moved + + only the z component of axis 3 (v3_z) is moved + + only v1_x and v2_y are moved + + only v1_x and v3_z are moved + + only v2_y and v3_z are moved + + only v1_x, v2_y, v3_z are moved + + all axis and angles, keeping the volume fixed + + the volume changes, keeping all angles fixed (i.e. only celldm(1) changes) + + only x and y components are allowed to change + + as above, keeping the area in xy plane fixed + + +BEWARE: if axis are not orthogonal, some of these options do not + work (symmetry is broken). If you are not happy with them, + edit subroutine init_dofree in file Modules/cell_base.f90 + + + + + + + + + + +label of the atom. Acceptable syntax: +chemical symbol X (1 or 2 characters, case-insensitive) +or chemical symbol plus a number or a letter, as in +"Xn" (e.g. Fe1) or "X_*" or "X-*" (e.g. C1, C_h; +max total length cannot exceed 3 characters) + + + + +mass of the atomic species [amu: mass of C = 12] +Used only when performing Molecular Dynamics run +or structural optimization runs using Damped MD. +Not actually used in all other cases (but stored +in data files, so phonon calculations will use +these values unless other values are provided) + + + + +File containing PP for this species. + +The pseudopotential file is assumed to be in the new UPF format. +If it doesn't work, the pseudopotential format is determined by +the file name: + +*.vdb or *.van Vanderbilt US pseudopotential code +*.RRKJ3 Andrea Dal Corso's code (old format) +none of the above old PWscf norm-conserving format + + + +
+ + + + + alat | bohr | angstrom | crystal | crystal_sg + + (DEPRECATED) alat + + + +Units for ATOMIC_POSITIONS: + + +atomic positions are in cartesian coordinates, in +units of the lattice parameter (either celldm(1) +or A). If no option is specified, 'alat' is assumed; +not specifying units is DEPRECATED and will no +longer be allowed in the future + + +atomic positions are in cartesian coordinate, +in atomic units (i.e. Bohr radii) + + +atomic positions are in cartesian coordinates, in Angstrom + + +atomic positions are in crystal coordinates, i.e. +in relative coordinates of the primitive lattice +vectors as defined either in card CELL_PARAMETERS +or via the ibrav + celldm / a,b,c... variables + + +atomic positions are in crystal coordinates, i.e. +in relative coordinates of the primitive lattice. +This option differs from the previous one because +in this case only the symmetry inequivalent atoms +are given. The variable space_group must indicate +the space group number used to find the symmetry +equivalent atoms. The other variables that control +this option are uniqueb, origin_choice, and +rhombohedral. + + + + + + +Specified atomic positions will be IGNORED and those from the +previous scf calculation will be used instead !!! + + + + + + + + label of the atom as specified in ATOMIC_SPECIES + + + + +atomic positions + +NOTE: each atomic coordinate can also be specified as a simple algebraic expression. + To be interpreted correctly expression must NOT contain any blank + space and must NOT start with a "+" sign. The available expressions are: + + + (plus), - (minus), / (division), * (multiplication), ^ (power) + + All numerical constants included are considered as double-precision numbers; + i.e. 1/2 is 0.5, not zero. Other functions, such as sin, sqrt or exp are + not available, although sqrt can be replaced with ^(1/2). + + Example: + C 1/3 1/2*3^(-1/2) 0 + + is equivalent to + + C 0.333333 0.288675 0.000000 + + Please note that this feature is NOT supported by XCrysDen (which will + display a wrong structure, or nothing at all). + + When atomic positions are of type crystal_sg coordinates can be given + in the following four forms (Wyckoff positions): + C 1a + C 8g x + C 24m x y + C 48n x y z + The first form must be used when the Wyckoff letter determines uniquely + all three coordinates, forms 2,3,4 when the Wyckoff letter and 1,2,3 + coordinates respectively are needed. + + The forms: + C 8g x x x + C 24m x x y + are not allowed, but + C x x x + C x x y + C x y z + are correct. + + + + + + + + + + + +component i of the force for this atom is multiplied by if_pos(i), +which must be either 0 or 1. Used to keep selected atoms and/or +selected components fixed in MD dynamics or +structural optimization run. + +With crystal_sg atomic coordinates the constraints are copied in all equivalent +atoms. + + 1 + + + + + + + + + + +
+ + + + + + + tpiba | automatic | crystal | gamma | tpiba_b | crystal_b | tpiba_c | crystal_c + + tbipa + + + +K_POINTS options are: + + +read k-points in cartesian coordinates, +in units of 2 pi/a (default) + + +automatically generated uniform grid of k-points, i.e, +generates ( nk1, nk2, nk3 ) grid with ( sk1, sk2, sk3 ) offset. +nk1, nk2, nk3 as in Monkhorst-Pack grids +k1, k2, k3 must be 0 ( no offset ) or 1 ( grid displaced +by half a grid step in the corresponding direction ) +BEWARE: only grids having the full symmetry of the crystal + work with tetrahedra. Some grids with offset may not work. + + +read k-points in crystal coordinates, i.e. in relative +coordinates of the reciprocal lattice vectors + + +use k = 0 (no need to list k-point specifications after card) +In this case wavefunctions can be chosen as real, +and specialized subroutines optimized for calculations +at the gamma point are used (memory and cpu requirements +are reduced by approximately one half). + + +Used for band-structure plots. +k-points are in units of 2 pi/a. +nks points specify nks-1 lines in reciprocal space. +Every couple of points identifies the initial and +final point of a line. pw.x generates N intermediate +points of the line where N is the weight of the first point. + + +As tpiba_b, but k-points are in crystal coordinates. + + +Used for band-structure contour plots. +k-points are in units of 2 pi/a. nks must be 3. +3 k-points k_0, k_1, and k_2 specify a rectangle +in reciprocal space of vertices k_0, k_1, k_2, +k_1 + k_2 - k_0: k_0 + \alpha (k_1-k_0)+ +\beta (k_2-k_0) with 0 <\alpha,\beta < 1. +The code produces a uniform mesh n1 x n2 +k points in this rectangle. n1 and n2 are +the weights of k_1 and k_2. The weight of k_0 +is not used. + + +As tpiba_c, but k-points are in crystal coordinates. + + + + + + + + + Number of supplied special k-points. + + + + + + + + + + + + + + + +Special k-points (xk_x/y/z) in the irreducible Brillouin Zone +(IBZ) of the lattice (with all symmetries) and weights (wk) +See the literature for lists of special points and +the corresponding weights. + +If the symmetry is lower than the full symmetry +of the lattice, additional points with appropriate +weights are generated. Notice that such procedure +assumes that ONLY k-points in the IBZ are provided in input + +In a non-scf calculation, weights do not affect the results. +If you just need eigenvalues and eigenvectors (for instance, +for a band-structure plot), weights can be set to any value +(for instance all equal to 1). + + + +
+ + + + + + + + + + + + + +These parameters specify the k-point grid +(nk1 x nk2 x nk3) as in Monkhorst-Pack grids. + + + + + + + + + + +The grid offsets; sk1, sk2, sk3 must be +0 ( no offset ) or 1 ( grid displaced by +half a grid step in the corresponding direction ). + + + + + + + + + + + + + + alat | bohr | angstrom + + +Unit for lattice vectors; options are: + +'bohr' / 'angstrom': + lattice vectors in bohr-radii / angstrom. + In this case the lattice parameter alat = sqrt(v1*v1). + +'alat' / nothing specified: + lattice vectors in units of the lattice parameter (either + celldm(1) or A). Not specifying units is DEPRECATED + and will not be allowed in the future. + +If neither unit nor lattice parameter are specified, +'bohr' is assumed - DEPRECATED, will no longer be allowed + + + + + + + + +Crystal lattice vectors (in cartesian axis): + v1(1) v1(2) v1(3) ... 1st lattice vector + v2(1) v2(2) v2(3) ... 2nd lattice vector + v3(1) v3(2) v3(3) ... 3rd lattice vector + + + + + + + + + +
+ + + + + +When this card is present the SHAKE algorithm is automatically used. + + + + + Number of constraints. + + + + + Tolerance for keeping the constraints satisfied. + + + + + + + + + +Type of constraint : + + +constraint on global coordination-number, i.e. the +average number of atoms of type B surrounding the +atoms of type A. The coordination is defined by +using a Fermi-Dirac. +(four indexes must be specified). + + +constraint on local coordination-number, i.e. the +average number of atoms of type A surrounding a +specific atom. The coordination is defined by +using a Fermi-Dirac. +(four indexes must be specified). + + +constraint on interatomic distance +(two atom indexes must be specified). + + +constraint on planar angle +(three atom indexes must be specified). + + +constraint on torsional angle +(four atom indexes must be specified). + + +constraint on the projection onto a given direction +of the vector defined by the position of one atom +minus the center of mass of the others. +G. Roma, J.P. Crocombette: J. Nucl. Mater. 403, 32 (2010), +doi:10.1016/j.jnucmat.2010.06.001 + + + + + + + + + + + + + + + +These variables have different meanings for different constraint types: + +'type_coord' : + constr(1) is the first index of the atomic type involved + constr(2) is the second index of the atomic type involved + constr(3) is the cut-off radius for estimating the coordination + constr(4) is a smoothing parameter + +'atom_coord' : + constr(1) is the atom index of the atom with constrained coordination + constr(2) is the index of the atomic type involved in the coordination + constr(3) is the cut-off radius for estimating the coordination + constr(4) is a smoothing parameter + +'distance' : + atoms indices object of the constraint, as they appear in + the ATOMIC_POSITIONS card + +'planar_angle', 'torsional_angle' : + atoms indices object of the constraint, as they appear in the + ATOMIC_POSITIONS card (beware the order) + +'bennett_proj' : + constr(1) is the index of the atom whose position is constrained. + constr(2:4) are the three coordinates of the vector that specifies + the constraint direction. + + + + + +Target for the constrain ( angles are specified in degrees ). +This variable is optional. + + + + +
+ + + + + + + + + +Occupations of individual states (MAX 10 PER ROW). +For spin-polarized calculations, these are majority spin states. + + + + + +Occupations of minority spin states (MAX 10 PER ROW) +To be specified only for spin-polarized calculations. + + + + +
+ + + + + +BEWARE: if the sum of external forces is not zero, the center of mass of + the system will move + + + + + + label of the atom as specified in ATOMIC_SPECIES + + + + +external force on atom X (cartesian components, Ry/a.u. units) + + + + + + + + + +
+ + + diff --git a/aiida_quantumespresso/calculations/helpers/__init__.py b/aiida_quantumespresso/calculations/helpers/__init__.py index bc015da31..3058e7909 100644 --- a/aiida_quantumespresso/calculations/helpers/__init__.py +++ b/aiida_quantumespresso/calculations/helpers/__init__.py @@ -66,7 +66,7 @@ def _check_and_convert(kw,val,expected_type): return outval def pw_input_helper(input_params, structure, - stop_at_first_error=False, flat_mode=False, version="5.4.0"): + stop_at_first_error=False, flat_mode=False, version="6.2"): """ Validate if the input dictionary for Quantum ESPRESSO is valid. Return the dictionary (possibly with small variations: e.g. convert