bsym.symmetry_group

class bsym.symmetry_group.SymmetryGroup(symmetry_operations=[])

Bases: object

SymmetryGroup class.

A SymmetryGroup object contains a set of SymmetryOperation objects.

e.g.:

SymmetryGroup( symmetry_operations=[ s1, s2, s3 ] )

where s1, s2, and s3 are SymmetryOperation objects.

SymmetryGroup objects can also be created from files using the class methods:

SymmetryGroup.read_from_file( filename )

and:

SymmetryGroup.read_from_file_with_labels( filename )

append(symmetry_operation)

Append a SymmetryOperation to this SymmetryGroup.

Parameters:symmetry_operation (SymmetryOperation) – The SymmetryOperation to add. Returns:self (SymmetryGroup)

by_label(label)

Returns the SymmetryOperation with a matching label.

Parameters:label (str) – The label identifying the chosen symmetry operation. Returns:The symmetry operation that matches this label. Return type:(SymmetryOperation)

class_str = 'SymmetryGroup'

extend(symmetry_operations_list)

Extend the list of symmetry operations in this SymmetryGroup.

Parameters:symmetry_operations_list (list) – A list of SymmetryOperation objects. Returns:self (SymmetryGroup)

labels

A list of labels for each SymmetryOperation in this spacegroup.

Parameters:None – Returns:A list of label strings. Return type:(list)

classmethod read_from_file(filename)

Create a SymmetryGroup object from a file.

The file format should be a series of numerical mappings representing each symmetry operation.

e.g. for a pair of equivalent sites:

# example input file to define the spacegroup for a pair of equivalent sites
1 2
2 1

Parameters:filename (str) – Name of the file to be read in. Returns:spacegroup (SymmetryGroup)

classmethod read_from_file_with_labels(filename)

Create a SymmetryGroup object from a file, with labelled symmetry operations.

The file format should be a series of numerical mappings representing each symmetry operation, prepended with a string that will be used as a label.

e.g. for a pair of equivalent sites:

# example input file to define the spacegroup for a pair of equivalent sites
E  1 2
C2 2 1

Parameters:filename (str) – Name of the file to be read in. Returns:spacegroup (SymmetryGroup)

save_symmetry_operation_vectors_to(filename)

Save the set of vectors describing each symmetry operation in this SymmetryGroup to a file.

Parameters:filename (str) – Name of the file to save to. Returns:None

size