# CASTEP¶

From the CASTEP website http://www.castep.org

CASTEP is a leading code for calculating the properties of materials from first principles. Using density functional theory, it can simulate a wide range of properties of materials proprieties including energetics, structure at the atomic level, vibrational properties, electronic response properties etc. In particular it has a wide range of spectroscopic features that link directly to experiment, such as infra-red and Raman spectroscopies, NMR, and core level spectra.

CASTEP is a commercial code, requiring a valid licence. If you do have a vaild licence, email support@hpc.cam.ac.uk who will be able to add you to the user group on the system.

## Running CASTEP on CSD3¶

Running CASTEP will require a simple script:

#!/bin/bash
#SBATCH --account MYACCOUNT
#SBATCH --partition skylake
#SBATCH --nodes 2
#SBATCH --ntasts 64
#SBATCH --time 02:00:00

module purge

which can be submitted to the queue with sbatch from the same directory as the problemname.param and problemname.cell input files. This will run on two nodes in pure MPI mode up to a limit of 2 hours. To run on more nodes the --nodes and --ntasks options should be adjusted and the timelimit can be changed with --time.