phonopy/doc/interfaces.md

4.5 KiB

(calculator_interfaces)=

Interfaces to calculators

The interfaces for VASP, WIEN2k, Quantum ESPRESSO (QE), ABINIT, Elk, SIESTA, CRYSTAL, DFTB+, TURBOMOLE, FHI-AIMS, CASTEP, ABACUS, and LAMMPS are built in to the usual phonopy command. See the command options and how to invoke each of them at {ref}force_calculators. {ref}LAMMPS interface <external_tools_phonolammps> is provided as an external tool by Abel Carreras.

(interfaces_to_force_calculators)=

List of force calculators

Short tutorials for the force calculators are found in the following pages.

:maxdepth: 1
vasp
wien2k
qe
abinit
siesta
elk
crystal
dftb+
turbomole
cp2k
aims
castep
Fleur
abacus
lammps

The VASP DFPT interface reads vasprun.xml and creates FORCE_CONSTANTS file.

:maxdepth: 1
vasp-dfpt

(interfaces-physical-units)=

Physical unit system for calculator

Physical unit systems used for the calculators are as follows:

          | Distance   Atomic mass   Force         Force constants
-----------------------------------------------------------------
VASP      | Angstrom   AMU           eV/Angstrom   eV/Angstrom^2
WIEN2k    | au (bohr)  AMU           mRy/au        mRy/au^2
QE        | au (bohr)  AMU           Ry/au         Ry/au^2
ABINIT    | au (bohr)  AMU           eV/Angstrom   eV/Angstrom.au
SIESTA    | au (bohr)  AMU           eV/Angstrom   eV/Angstrom.au
Elk       | au (bohr)  AMU           hartree/au    hartree/au^2
CRYSTAL   | Angstrom   AMU           eV/Angstrom   eV/Angstrom^2
TURBOMOLE | au (bohr)  AMU           hartree/au    hartree/au^2
CP2K      | Angstrom   AMU           hartree/au    hartree/Angstrom.au
FHI-AIMS  | Angstrom   AMU           eV/Angstrom   eV/Angstrom^2
Fleur     | au (bohr)  AMU           hartree/au    hartree/au^2
CASTEP    | Angstrom   AMU           eV/angstrom   eV/angstrom^2
ABACUS    | au (bohr)  AMU           eV/angstrom   eV/angstrom.au
LAMMPS    | Angstrom   AMU           eV/Angstrom   eV/Angstrom^2

For these sets of physical properties, phonon frequency is calculated in THz.

Default file name, value, and conversion factor

Default unit cell file name for calculator

Without specifying -c option, default file names of unit cell shown below is searched in current directory. When generating supercells with -c option, the default supercell file names based on those shown below are used.

VASP      | POSCAR        | SPOSCAR
WIEN2k    | case.struct   | case.structS
QE        | unitcell.in   | supercell.in
ABINIT    | unitcell.in   | supercell.in
SIESTA    | input.fdf     | supercell.fdf
Elk       | elk.in        | supercell.in
CRYSTAL   | crystal.o     | -
DFTB+     | geo.gen       | geo.genS
TURBOMOLE | control       | -
CP2K      | unitcell.inp  | -
FHI-AIMS  | geometry.in   | geometry.in.supercell
Fleur     | fleur.in      | supercell.in
CASTEP    | unitcell.cell | supercell.cell
ABACUS    | STRU          | STRU.in
LAMMPS    | unitcell      | supercell

Default displacement distances

Without specifying DISPLACEMENT_DISTANCE tag or --amplitude option, default displacement distance is used when creating supercells with displacements CREATE_DISPLACEMENTS = .TRUE. or -d option. The default value is dependent on calculator, and the list is shown below:

VASP      | 0.01 Angstrom
WIEN2k    | 0.02 au (bohr)
QE        | 0.02 au (bohr)
ABINIT    | 0.02 au (bohr)
SIESTA    | 0.02 au (bohr)
Elk       | 0.02 au (bohr)
CRYSTAL   | 0.01 Angstrom
DFTB+     | 0.01 au (bohr)
TURBOMOLE | 0.02 au (bohr)
CP2K      | 0.01 Angstrom
FHI-AIMS  | 0.01 Angstrom
Fleur     | 0.02 au (bohr)
CASTEP    | 0.01 Angstrom
ABACUS    | 0.02 au (bohr)
LAMMPS    | 0.01 Angstrom

(frequency_default_value_interfaces)=

Default unit conversion factor of phonon frequency to THz

VASP      | 15.633302
WIEN2k    | 3.44595837
QE        | 108.97077
ABINIT    | 21.49068
SIESTA    | 21.49068
Elk       | 154.10794
CRYSTAL   | 15.633302
DFTB+     | 154.10794
TURBOMOLE | 154.10794
CP2K      | 112.10516
FHI-AIMS  | 15.633302
Fleur     | 154.10794
CASTEP    | 15.633302
ABACUS    | 21.49068
LAMMPS    | 15.633302

(nac_default_value_interfaces)=

Default unit conversion factor for non-analytical term correction

VASP      | 14.399652
WIEN2k    | 2000
QE        | 2
ABINIT    | 51.422090
SIESTA    | 51.422090
Elk       | 1
CRYSTAL   | 14.399652
DFTB+     | 14.399652
TURBOMOLE | 1
CP2K      | None (N/A)
FHI-AIMS  | 14.399652
Fleur     | 1 (but feature N/A)
CASTEP    | 14.399652
ABACUS    | 51.422090
LAMMPS    | 14.399652