VASP

VASP#

This guide covers using VASP (Vienna Ab initio Simulation Package) for density functional theory calculations on NMTHPC.

VASP License#

Warning

VASP is commercial software requiring a valid license. You must provide proof of license before accessing VASP on NMTHPC.

Contact hpc@nmthpc.atlassian.net with your VASP license information.

Loading VASP#

$ module avail vasp
$ module load vasp/6.4.0

Running VASP#

Basic VASP Calculation#

Required input files:

  • INCAR: Calculation parameters

  • POSCAR: Atomic positions

  • POTCAR: Pseudopotentials

  • KPOINTS: k-point mesh

Example SLURM script:

#!/bin/bash
#SBATCH --job-name=vasp_calc
#SBATCH --output=vasp_%j.out
#SBATCH --ntasks=16
#SBATCH --mem-per-cpu=4G
#SBATCH --time=24:00:00

module load vasp/6.4.0

mpirun vasp_std

VASP Variants#

Standard version (vasp_std):

mpirun vasp_std

Gamma-point only (vasp_gam):

mpirun vasp_gam

Non-collinear (vasp_ncl):

mpirun vasp_ncl

GPU-Accelerated VASP#

For GPU nodes:

#!/bin/bash
#SBATCH --partition=gpu
#SBATCH --gres=gpu:1
#SBATCH --ntasks=4
#SBATCH --mem=64G
#SBATCH --time=48:00:00

module load vasp/6.4.0-gpu

mpirun vasp_gpu

Example Calculations#

Structural Optimization#

INCAR:

ISTART = 0
ICHARG = 2
ENCUT = 500
ISMEAR = 0
SIGMA = 0.05
IBRION = 2
NSW = 100
ISIF = 3
EDIFFG = -0.01

Band Structure#

Step 1: Self-consistent calculation:

ISTART = 0
ICHARG = 2
ENCUT = 500

Step 2: Band structure (INCAR):

ISTART = 1
ICHARG = 11
ENCUT = 500
ICHARG = 11

Best Practices#

  1. Test convergence: k-points and ENCUT

  2. Checkpointing: VASP writes WAVECAR and CHGCAR

  3. Monitor output: Check OSZICAR during run

  4. Resource requests: Match tasks to system

  5. Time limits: DFT calculations can be long

Post-Processing#

Extract energy:

$ grep "free energy" OUTCAR | tail -1

Parse OSZICAR:

$ tail OSZICAR

Questions?#

Contact hpc@nmthpc.atlassian.net for VASP support.