VASP
VASP is an ab initio DFT program for computing electronic structures of up to few hundreds of atoms.
This page briefly describes how to use VASP on puhti.csc.fi. Usage on mahti is very similar. That said, VASP is a program which usage requires some experience. It is advised that new VASP users start out with a supervisor or an experienced colleague.
Available
See available VASP versions in puhti.csc.fi with command
module avail vasp
License
The usage of VASP requires a license, which must be acquired directly from the developers of the software.
After acquiring the license, please send email to servicedesk@csc.fi, including the email address you have registered for the VASP license and your user name at CSC.
Usage
Precompiled VASP executables and pseudopotentials are available through module environment. Use command
module show vasp
to see more detailed information.
An example batch job script for a small test
#!/bin/bash
#SBATCH --time=00:15:00
#SBATCH --partition=test
#SBATCH --ntasks=4
#SBATCH --mem-per-cpu=1GB
#SBATCH --account=<project>
module load vasp
srun vasp_std
For more options and details, see Creating a batch job script.
Performance optimization
First, the performance of VASP depends crucially on the parameters in the INCAR file that control how the different k-points, bands and FFT coefficients are distributed among the MPI tasks, and that the correct version (std/gam/ncl) of the executable is used.
Second, the provided prebuild executables are built as "vanilla" as
possible, and provide a reasonable baseline. The performance
optimization for large experiments should be done per case basis. The
commands that created the prebuilt executables are in
$VASPDIR/README.sh
, and can be used as a starting point
for building more optimized, and/or otherwise modified executables.