vasppy.kpoints module

class AutoKPoints(title: str, subdivisions: ndarray, grid_centering: str | None = 'G', shift: ndarray | None = None)[source]

Bases: object

Class for automatic k-point generation data in KPOINTS.

Initialise an AutoKPoints object.

Parameters:

  • title (str) – The first line of the file, treated as a comment by VASP.

  • subdivisions – (np.ndarray(int, int, int)): Numbers of subdivisions along each reciprocal lattice vector.

  • grid_centering (str, optional) – Specify gamma-centered (G) or the original Monkhorst-Pack scheme (MP). Default is ‘G’.

  • shift – (np.ndarray(float, float, float), optional): Optional shift of the mesh (s_1, s_2, s_3). Default is ( [ 0., 0., 0. ] ).

Returns:

None

Raises:

ValueError – If an unrecognised grid-centering option is passed in.

get_convergence_testing_kspacing(reciprocal_lattice_vectors: ndarray, kspacing_range: tuple[float, float] = (0.1, 0.8), step: float = 0.02) → tuple[float, ...][source]

Generate a range of minimum allowed distances between k-points (KSPACING) for convergence testing. This function ensures that no two values of KSPACING are generated that correspond to the same k-point mesh.

Parameters:

  • reciprocal_lattice_vectors (np.ndarray) – The reciprocal lattice vectors. These can be retrieved from ASE as atoms.cell.reciprocal() or from Pymatgen as

  • structure.lattice.reciprocal_lattice_crystallographic.matrix. –

  • kspacing_range (tuple[float, float]) – The minimum and maximum KSPACING values. Defaults to (0.1, 0.8).

  • step (float) – The interval between KSPACING values to be tested. Defaults to 0.02.

Returns:

A range of KSPACING values which all correspond to distinct k-point grids.

Return type:

tuple[float, …]

get_subdivisions_from_kspacing(kspacing: float, reciprocal_lattice_vectors: ndarray) → tuple[int, ...][source]

Calculate subdivisions along reciprocal lattice vectors from the miniumum allowed distance between k-points (KSPACING).

Parameters:

  • kspacing (float) – The minimum allowed distance between k-points.

  • reciprocal_lattice_vectors (np.ndarray) – The reciprocal lattice vectors. These can be retrieved from ASE as atoms.cell.reciprocal() or from Pymatgen as

  • structure.lattice.reciprocal_lattice_crystallographic.matrix. –

Returns:

The subdivisions along each reciprocal lattice vector.

Return type:

tuple[int, …]