phono3py/doc/interfaces.md

2.2 KiB

(calculator_interfaces)=

Interfaces to calculators

Currently the built-in interfaces for VASP, QUANTUM ESPRESSO (QE), CRYSTAL, Abinit, and TURBOMOLE are prepared. VASP is the default interface and no special option is necessary to invoke it, but for the other interfaces, each special option has to be specified, e.g. --qe, --crystal, --abinit, or --turbomole

:maxdepth: 1
vasp
qe
crystal
turbomole

Calculator specific behaviors

Physical unit

The interfaces for VASP, QE (pw), CRYSTAL, Abinit, and TURBOMOLE are built in to the phono3py command.

For each calculator, each physical unit system is used. The physical unit systems used for the calculators are summarized below.

| calculator | unit-cell | FORCES_FC3  | phono3py_disp.yaml |
|------------|-----------|-------------|--------------------|
| VASP       | Angstrom  | eV/Angstrom | Angstrom           |
| QE (pw)    | au (bohr) | Ry/au       | au                 |
| CRYSTAL    | Angstrom  | eV/Angstrom | Angstrom           |
| Abinit     | au (bohr) | eV/Angstrom | au                 |
| TURBOMOLE  | au (bohr) | hartree/au  | au                 |

FORCES_FC3, FORCES_FC2, and phono3py_disp.yaml have the same physical units.

Always (irrespective of calculator interface) the physical units of 2nd and 3rd order force constants that are to be stored in fc2.hdf5 and fc3.hdf5 are \text{eV}/\text{Angstrom}^2 and \text{eV}/\text{Angstrom}^3, respectively.

(default_unit_cell_file_name_for_calculator)=

Default unit cell file name

Default unit cell file names are also changed according to the calculators::

| calculator| filename    |
|-----------|-------------|
| VASP      | POSCAR      |
| QE        | unitcell.in |
| CRYSTAL   | crystal.o   |
| Abinit    | unitcell.in |
| TURBOMOLE | control     |

(default_displacement_distance_for_calculator)=

Default displacement distance created

Default displacement distances created by -d option without --amplitude option are respectively as follows::

| calculator | distance       |
|------------|----------------|
| VASP       | 0.03 Angstrom  |
| QE         | 0.06 au (bohr) |
| CRYSTAL    | 0.03 Angstrom  |
| Abinit     | 0.06 au (bohr) |
| TURBOMOLE  | 0.06 au (bohr) |