diff --git a/docs/source/howto/calculations/pw.rst b/docs/source/howto/calculations/pw.rst index b75bdb3ed..6cb06996f 100644 --- a/docs/source/howto/calculations/pw.rst +++ b/docs/source/howto/calculations/pw.rst @@ -246,6 +246,60 @@ Similar to the pseudopotentials themselves, these can easily be retrieved for an Be sure to specify the ``unit`` as ``Ry`` as that is the unit that ``pw.x`` will expect. +How to run an initialization-only calculation +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Specify ``ONLY_INITIALIZATION: True`` in the ``settings`` input: + +.. code-block:: python + + builder = load_code('pw').get_builder() + builder.settings = Dict({'ONLY_INITIALIZATION': True}) + +If this setting is specified, the plugin will write the file ``aiida.EXIT`` in the working directory of the calculation. +This will cause Quantum ESPRESSO to just run the preamble of the code and then shutdown cleanly. + + +How to run a gamma-only calculation +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Specify ``GAMMA_ONLY: True`` in the ``settings`` input: + +.. code-block:: python + + builder = load_code('pw').get_builder() + builder.settings = Dict({'GAMMA_ONLY': True}) + + +How to fix the coordinates of atoms +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Quantum ESPRESSO pw.x allows to optionally fix the coordinates of atoms during relaxation and molecular-dynamics simulations. +This functionality is enabled in ``PwCalculation`` through the ``FIXED_COORDS`` setting which is a list of length equal to the number of sites in the input structure. +Each element is a list of length three containing booleans, where ``True`` means that the position of the site in that direction should be fixed. +For example: + +.. code-block:: python + + builder = load_code('pw').get_builder() + builder.settings = Dict({'FIXED_COORDS': [[False, False, False], [False, False, True]]}) + +will fix the position of the second site along the z-axis only. +All other coordinates are allowed to change. + + +How to retrieve additional files +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +The ``PwCalculation`` plugin will retrieve the most important and common output files by default. +To retrieve additional output files, specify the list of files in the ``ADDITIONAL_RETRIEVE_LIST`` key in the ``settings`` input: + +.. code-block:: python + + builder = load_code('pw').get_builder() + builder.settings = Dict({'ADDITIONAL_RETRIEVE_LIST': ['custom-file.txt', 'some-other.xml']}) + + .. |starting_magnetization| replace:: ``starting_magnetization`` .. _starting_magnetization: https://www.quantum-espresso.org/Doc/INPUT_PW.html#idm287