# VASP 2016

## Introduction

The Vienna Ab initio Simulation Package (VASP) is a computer program for atomic scale materials modelling, e.g. electronic structure calculations and quantum-mechanical molecular dynamics, from first principles.

VASP computes an approximate solution to the many-body Schrödinger equation, either within density functional theory (DFT), solving the Kohn-Sham equations, or within the Hartree-Fock (HF) approximation, solving the Roothaan equations. Hybrid functionals that mix the Hartree-Fock approach with density functional theory are implemented as well. Furthermore, Green's functions methods (GW quasiparticles, and ACFDT-RPA) and many-body perturbation theory (2nd-order Møller-Plesset) are available in VASP.

In VASP, central quantities, like the one-electron orbitals, the electronic charge density, and the local potential are expressed in plane wave basis sets. The interactions between the electrons and ions are described using norm-conserving or ultrasoft pseudopotentials, or the projector-augmented-wave method.

To determine the electronic groundstate, VASP makes use of efficient iterative matrix diagonalisation techniques, like the residual minimisation method with direct inversion of the iterative subspace (RMM-DIIS) or blocked Davidson algorithms. These are coupled to highly efficient Broyden and Pulay density mixing schemes to speed up the self-consistency cycle. ^{1}

## Installed version(s)

The following versions are installed and currently available...

... on environment *hpc-env/8.3*:

**VASP/5.4.1**-intel-2019b**VASP/5.4.4**-intel-2019b**VASP/5.4.4**-intel-2019b-Wannier90**VASP/6.2.1**-intel-2019b-Wannier90

**p4vasp/0.3.30**-Singularity

(visualisation tool for VASP output)

## Loading / Using VASP

To load the desired version of the module, use the *module load* command, e.g.

module load hpc-env/8.3 module load VASP

After loading the VASP module you will have access to the three binaries `vasp_gam`, `vasp_ncl`, and `vasp_std` as well as to a folder containing potentials, whichs path is stored at the envoironment variable `$POTENTIALS` after loading the module:

ls -l $POTENTIALS ## lists folder containing potentials echo $POTENTIALS ## prints out path to potentials directory

## Documentation

The full documentation can be found here.