Calculator

Contents

Calculator#

The Vasp calculator is the main interface for running VASP calculations.

Basic Usage#

from ase.build import bulk
from vasp import Vasp

atoms = bulk('Si', 'diamond', a=5.43)

calc = Vasp(
    atoms=atoms,
    xc='PBE',
    encut=400,
    kpts=(8, 8, 8),
)

energy = calc.potential_energy
forces = calc.forces
stress = calc.stress

Constructor Parameters#

Parameter	Type	Description
`atoms`	Atoms	ASE Atoms object
`label`	str	Calculation directory name
`runner`	Runner	Execution backend
`xc`	str	Exchange-correlation functional
`encut`	float	Plane-wave cutoff (eV)
`kpts`	tuple	K-point mesh
…	…	Any VASP parameter

Properties#

calc.potential_energy  # Total energy (eV)
calc.forces            # Forces (eV/Å)
calc.stress            # Stress tensor (eV/Å³)
calc.atoms             # Current atoms
calc.parameters        # All parameters
calc.directory         # Working directory
calc.results           # All results dict

Methods#

calc.read_results()           # Parse output files
calc.read_doscar()            # Read DOS data
calc.read_procar()            # Read projected DOS
calc.read_eigenval()          # Read eigenvalues
calc.get_work_function()      # Calculate work function
calc.get_band_gap_from_doscar()  # Get band gap

Input File Generation#

VASP input files are generated automatically:

INCAR: From keyword parameters
POSCAR: From atoms object
KPOINTS: From kpts parameter
POTCAR: From pseudopotential path

Output Parsing#

Results are parsed from VASP output files:

OUTCAR: Energy, forces, stress, magnetic moments
vasprun.xml: All results in structured format
DOSCAR: Density of states
EIGENVAL: Band energies
LOCPOT: Electrostatic potential