lattice_symmetry - Determines how the lattice group is obtained.
character; AUTO, USER; AUTO
symmetry_mod; point_group_obj; pg%o%mode (AUTO or USER)
default is used
For AUTO, the lattice group is generated from the lattice.
For USER, the lattice group is read from file lgroup with format given below.
The lattice group is used to close the Monkhorst-Pack k-point mesh.
list_lattice_group - Prints the lattice-group operations to diaryf.
logical; .TRUE., .FALSE.; .FALSE.
symmetry_mod; NA; NA
default is used
list_space_group - Prints the space-group operations to diaryf.
logical; .TRUE., .FALSE.; .FALSE.
symmetry_mod; NA; NA
default is used
Note: The matrices are printed in the lattice representation. To compare these with the matrices given in Burns and Glazer, the printed matrices must be transformed to the cartesian representation.
save_lattice_group - Save a new lattice group file.
logical;.true., .false.; .false.
symmetry_mod; NA; NA
default is used
The file is saved in the run directory with the name “new_lgroup”. The format is as follows:
number_of_point_operators number_of_translations_per_point_operation
<space>
3×3 matrix denoting the first point operator (in lattice representation)
<space>
3×3 matrix denoting the next point operator (in lattice representation)
<space>
.
.
save_space_group - Save a new space group.
Logical; .true., .false.; .false.
symmetry_mod; NA; NA
default is used
The file is saved in the run directory with the name “new_sgroup”. The format is as follows:
# of point operators # of translations per point operation
<space>
3×3 matrix denoting the first point operator (in lattice representation)
first translation for the first point operator
second translation for the first point operator
.
.
last translation for the first point operator
<space>
3×3 matrix denoting the next point operator (in lattice representation)
first translation for the next point operator
second translation for the next point operator
.
.
last translation for the next point operator
<space>
.
.
sg_tolerance - Tolerance used to determine valid atom permutations.
real; > sg_tolerance/minimum-lattice-vector_magnitude > 1.0e-4; tolerance/minimum-lattice-vector-magnitude = 1.0e-8
symmetry_mod; space_group_obj; sg%o%tol_aperm
default is used

Note: If a run stops with the message “ERROR: unknown point-group type” in the error files, this indicates that the atom positions are slightly off of symmetry positions. The user should either add more digits to the atom positions in the crystal file or loosen sg_tolerance. Likewise if the space-group symmetry is not as large as expected.
symmetrize_atoms - Symmetrizes the starting atom positions.
character; ON, OFF; OFF
external_mod; NA; NA
default is used
symmetry - Determines whether or not space-group symmetry is used.
character; FULL, AUTO, OFF; AUTO
symmetry_mod; space_group_obj; sg%o%mode
default is used
For FULL, the space group is generated from the lattice group and atom positions. A new space group is generated when the lattice group or atom positions change.
For AUTO, the space group is generated from the lattice group and atom positions. A new space group is generated when the lattice group changes and when the old space group is not compatible with new atom positions.
For OFF, the trivial space group (C_1) is generated.
The space group (augmented by inversion if it is not already present) is used to reduce the closed Monkhorst-Pack points.

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