5.7. [config] section

This section specifies alloy coordination, etc. An example is shown as follows:

[config]
unitcell = [[8.1135997772, 0.0000000000, 0.0000000000],
            [0.0000000000, 8.1135997772, 0.0000000000],
            [0.0000000000, 0.0000000000, 8.1135997772]]
supercell = [1,1,1]

[[config.base_structure]]
type = "O"
coords = [
    [0.237399980, 0.237399980, 0.237399980],
    [0.762599945, 0.762599945, 0.762599945],
    ...
    [0.262599975, 0.262599975, 0.762599945],
    ]

[[config.defect_structure]]
coords = [
    [0.000000000, 0.000000000, 0.000000000],
    [0.749999940, 0.249999985, 0.499999970],
    ...
    [0.124999993, 0.624999940, 0.124999993],
    ]
[[config.defect_structure.groups]]
name = 'Al'
# species = ['Al']    # default
# coords = [[[0,0,0]]]  # default
num = 16
[[config.defect_structure.groups]]
name = 'Mg'
# species = ['Mg']    # default
# coords = [[[0,0,0]]]  # default
num = 8

5.7.1. Input Format

Keywords and their values are specified by a keyword and its value in the form keyword = value. Comments can also be entered by adding # (Subsequent characters are ignored).

5.7.2. Key words

  • Specify lattice

    • unitcell

      Format : list

      Description : Lattice vector \(\bf{a}, \bf{b}, \bf{c}\) by the list format [ \(\bf{a}, \bf{b}, \bf{c}\) ] .

    • supercell

      Format : list

      Description : The size of super lattice by the list format[ \(\bf{a}, \bf{b}, \bf{c}\) ].

  • [[config.base_structure]] section

    type and coords specify the atomic species that do not move in Monte Carlo calculation and their coordinates.

    If there are multiple atomic species, specify multiple [[config.base_structure]] sections.

    • type

      Format : str

      Description : Atomic specie.

    • coords

      Format : list of lists or str

      Description : Coordinates. Specify a list of N elements (number of atoms) arranged in 3 elements representing 3D coordinates, or a string of coordinates arranged in N rows and 3 columns.

  • [[config.defect_structure]] section

    This sections specifies the lattice coordinates (coords) and atoms (or atom groups) (groups) that can reside on those lattice sites. Monte Carlo sampling is performed on the lattice specified in this section. In Ver. 1.0, conversion tools from POSCAR and cif will be available.

    • coords

      Format : list of lists or str

      Description : The coordinates of the lattice sites where atoms reside. A list of N elements (number of atoms) arranged in 3 elements representing 3D coordinates, or a string of coordinates arranged in N rows and 3 columns.

    • [[config.defect_structure.groups]] section

      The atom group information to be updated by Monte Carlo.

      • name

        Format : str

        Description : The name of atomic group.

      • species

        Format : list

        Description : The atomic species belonging to the atom group. The default value is a list containing only one specified by name. A vacancy can be represented by an empty list [].

      • coords

        Format : list of lists of lists or str

        Description : The coordinates of each atom in the atom group in each direction of local orientation. N (number of atoms) three-element lists, each of which is a list of three elements representing three-dimensional coordinates, is specified as a three-fold list, arranged by orientation. For example, if there are two atoms in the atom group and there are three different orientations, x,y,z, then coords can be specified as:

        coords = [
[ # dir-1
[0.0, 0.0, 0.0], [0.5, 0.0, 0.0]
],
[ # dir-2
[0.0, 0.0, 0.0], [0.0, 0.5, 0.0]
],
[ # dir-3
[0.0, 0.0, 0.0], [0.0, 0.0, 0.5]
],
]

        The default value is [[0.0, 0.0, 0.0]], so this keyword can be omitted if there is only one atom in the atom group.

      • relaxation

        Format : list of lists or str

        Description : Whether to optimize structure (coordinates) or not for each atom and dimension. A list of N elements (number of atoms) with 3 booleans (“true” or “false”), or a string of “true” or “false” arranged in N rows and 3 columns. Default is ["true", "true", "true"] for all the atoms.

      • magnetization

        Format : list

        Description : Magnetization (the difference between the number of up and down electrons) for each atom. Default is 0.0 for all the atoms.

      • num

        Format : int

        Description : The number of atom groups of the type specified in this section.