cubic#

libcasm.xtal.prims.cubic(
a: float | None = None,
occ_dof: list[str] = ['A', 'B'],
local_dof: list[DoFSetBasis] = [],
global_dof: list[DoFSetBasis] = [],
occupants: dict[str, Occupant] = {},
title: str = 'prim',
) → Prim[source]#

Construct a simle cubic Prim

Parameters:

  • a (Optional[float] = None) – Specify the cubic lattice parameter \(a\).

  • occ_dof (list[str] = ["A", "B"]) – Labels (‘orientation names’) of occupants allowed on the basis site. The values may either be (i) the name of an isotropic atom (i.e. “Mg”) or vacancy (“Va”), or (ii) a key in the occupants dictionary (i.e. “H2O”, or “H2_xx”). The names are case sensitive, and “Va” is reserved for vacancies.

  • local_dof (list[DoFSetBasis]=[]) – Continuous DoF allowed on the basis site. No effect if empty.

  • global_dof (list[DoFSetBasis]=[]) – Global continuous DoF allowed for the entire crystal.

  • occupants (dict[str, Occupant]=[]) – Occupant allowed in the crystal. The keys are labels (‘orientation names’) used in the occ_dof parameter. This may include isotropic atoms, vacancies, atoms with fixed anisotropic properties, and molecular occupants. A seperate key and value is required for all species with distinct anisotropic properties (i.e. “H2_xy”, “H2_xz”, and “H2_yz” for distinct orientations, or “A.up”, and “A.down” for distinct collinear magnetic spins, etc.).

  • title (str="prim") – A title for the prim. When the prim is used to construct a cluster expansion, this must consist of alphanumeric characters and underscores only. The first character may not be a number.

Returns:

prim – A simple cubic Prim

Return type:

Prim

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