velph init

velph init#

velph init with command options will generate modified velph.toml from the template.

% velph init [OPTIONS] CELL_FILENAME PROJECT_FOLDER

velph init --help shows short documents of the options. Two arguments have to be specified, POSCAR-format crystal structure and directory name that is created where velph.toml is stored. The available options are explained below. Some options can be specified in [init.options] section of the velph-toml template file (see velph init template).

velph init options#

--template-toml#

Using this option, velph.toml like file is read as the template instead of the template hard coded in velph code.

--tolerance#

This is used for the symmetry check tolerance in Angstrom. Symmetry is searched always even without --symmetrize-cell.

--symmetrize-cell#

By default (no-symmetrize), the input POSCAR-type structure is simply used as the unit cell. With --symmetrize-cell, input POSCAR-type structure is symmetrized and standardized conventional unit cell and primitive cell (“unitcell” and “primitive_cell”, respectively) are written in velph.toml.

--no-find-primitive#

By this option, the input POSCAR-type structure is used as the primitive cell even if it is not a primitive cell.

--kspacing and --kspacing-dense#

Sampling k-point meshes are calculated from these values in the similar way to VASP KSPACING definition by overwriting the template.

--max-num-atoms#

Supercell shape is determined so that its number of atoms is equal or less than this number respecting the crystallographic point group. Use of this option requires --symmetrize-cell.

--dim#

Supercell shape is determined by three integer values that extend along a, b, and c axes of the unit cell, respectively. See also --supercell-matrix.

--supercell-matrix#

Supercell shape is determined by nine integer values (v1, …, v9) that corresponds to a 3x3 matrix [[v1, v2, v3], [v4, v5, v6], [v7, v8, v9]].

--cell-for-relax#

This chooses unit cell or primitive cell for structure optimization (relax). The default is unitcell. Specify primitive to use primitive cell.

--cell-for-nac#

This chooses unit cell or primitive cell for NAC calculation (nac). The default is primitive. Specify primitive to use primitive cell.

--primitive-cell-choice#

Primitive cell choice, “standardized” (default) or “reduced”.

--use-grg#

Use generalized regular grid.

--amplitude#

Distance of displacements in Angstrom.

--magmom#

String corresponding to INCAR MAGMOM tag value for unit cell, e.g., “24*1” or “0 0 1”. This is similar to MAGMOM tag in phonopy, see https://phonopy.github.io/phonopy/setting-tags.html#magmom. In velph, the asterisk symbol (*) is supported.

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