do not output spin info for lmp format

Author: OutisLi

dpdata/lammps/lmp.py

@@ -484,7 +484,7 @@ def rotate_to_lower_triangle(
     return cell, coord
 
 
-def from_system_data(system, f_idx=0):
+def from_system_data(system, f_idx=0, output_spins=False):
     ret = ""
     ret += "\n"
     natoms = sum(system["atom_numbs"])
@@ -529,7 +529,7 @@ def from_system_data(system, f_idx=0):
         + "\n"
     )  # noqa: UP031
 
-    if "spins" in system:
+    if "spins" in system and output_spins:
         coord_fmt = (
             coord_fmt.strip("\n")
             + " "
@@ -544,7 +544,7 @@ def from_system_data(system, f_idx=0):
         )  # noqa: UP031
         spins_norm = np.linalg.norm(system["spins"][f_idx], axis=1)
     for ii in range(natoms):
-        if "spins" in system:
+        if "spins" in system and output_spins:
             if spins_norm[ii] != 0:
                 ret += coord_fmt % (
                     ii + 1,

dpdata/plugins/lammps.py

@@ -108,7 +108,7 @@ def from_system(
         register_charge(data)
         return data
 
-    def to_system(self, data, file_name: FileType, frame_idx=0, **kwargs):
+    def to_system(self, data, file_name: FileType, frame_idx=0, output_spins=False, **kwargs):
         """Dump the system in lammps data format.
 
         Parameters
@@ -119,11 +119,14 @@ def to_system(self, data, file_name: FileType, frame_idx=0, **kwargs):
             The output file name
         frame_idx : int
             The index of the frame to dump
+        output_spins : bool, optional
+            Whether to output spin information columns. Default is False.
+            When True, outputs additional columns for spin direction and magnitude.
         **kwargs : dict
             other parameters
         """
         assert frame_idx < len(data["coords"])
-        w_str = dpdata.lammps.lmp.from_system_data(data, frame_idx)
+        w_str = dpdata.lammps.lmp.from_system_data(data, frame_idx, output_spins=output_spins)
         with open_file(file_name, "w") as fp:
             fp.write(w_str)