principia_materia.translation_group.kpoints module

class principia_materia.translation_group.kpoints.Kpoints(vec, supa, pg='C1', strict_symmetry=True, tol=1e-06)

Bases: Lattice

A list of K-points that fit in a given supercell.

Parameters:

• vec (array of float, shape(dim, dim)) – The lattice vectors, in row convention.

• supa (array of int, shape(dim, dim)) – Super lattice matrix.

• pg (str or a PointGroup object) – The point group of the lattice.

• strict_symmetry (bool, optional, default to True) – If True, lattice points must rotate into a point that also fits in the cell.

• tol (float, optional, default to 1.0E-6) – Tolerance threshold.

copy()

Return a copy of the object.

Returns:

new – A copy of the object itself.

Return type:

Kpoints

find_irreducible_lattice_points()

Find the irreducible set of k-points under the given symmetry.

get_index(vecs)

Find the index of a given K-vector or a list of K-vectors

property invsupa

The inverse of the supercell matrix.

property irreducible_kpoints

The irreducible k-points.

property irreducible_kpoints_index_map

The corresponding irreducible k-point index in the k-point list for each k-point.

property irreducible_kpoints_map

The corresponding irreducible k-point index in the irreducible k-point list for each k-point.

property irreducible_kpoints_mult

The multiplicity of each irreducible k-point.

property irreducible_kpoints_trans

The name of the operation takes the k-points at its index to one of the irreducible k-points.

property kpoints

The k-points that fit in the supercell.

kpoints_to_rlattice(vecs)

Convert Fraction K-vector(s) to reciprocal lattice points

Parameters:

vecs (array of Fraction, same shape as vecs) – The K-vectors (q-points).

Returns:

retval – An array of a series of arrays of the reciprocal lattice points (p-points).

Return type:

array of int, shape(N, dim) or shape(dim, )

property multiplicity

The multiplicity of the supercell.

rlattice_to_kpoints(vecs)

Convert reciprocal lattice points to Fraction K-vector(s)

Parameters:

vecs (array of int, shape(N, dim) or shape(dim, )) – An array of a series of arrays of the reciprocal lattice points (p-points).

Returns:

retval – The K-vectors (q-points).

Return type:

array of Fraction, same shape as vecs

property rotated_kpoints

Dictionary of how what each k-points rotate into for each group operation. (Indices)

property rvec_bz

The reciprocal lattice vector of the supercell.

property supa

The supercell matrix.

to_dict()

Return a dictionary containing key information about the LatticeFTG object.

principia_materia.translation_group.kpoints.get_kpoints_io_wrapper(title='Kpoints')

YAML data wrapper for Kpoints class.