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CASTEP is software for calculating the properties of materials. It models various properties including energetics, atomic structure, vibrational properties, electronic response etc.

CASTEP is available as a module on Apocrita. Both serial (castep.serial) and MPI versions (castep.mpi) are available.


CASTEP requires AVX2 instructions and therefore must be run on a node which supports this instruction set. For serial jobs, this can be achieved using the -l avx2 option in your job script. For parallel jobs the -l infiniband= setting will select the appropriate nodes for you.

To run the default version of CASTEP, simply load the castep module:

$ module load castep
$ castep.serial
castep <seedname>                : Run files <seedname>.cell [and <seedname>.param]
  "    [-d|--dryrun] <seedname>  : Perform a dryrun calculation on files <seedname>.cell
  "    [-s|--search] <text>      : print list of keywords with <text> match in description
  "    [-v|--version]            : print version information
  "    [-h|--help] <keyword>     : describe specific keyword in <>.cell or <>.param
  "         "      all           : print list of all keywords
  "         "      basic         : print list of basic-level keywords
  "         "      inter         : print list of intermediate-level keywords
  "         "      expert        : print list of expert-level keywords
  "         "      dummy         : print list of dummy keywords

For full usage documentation, run castep.serial -h.


To use castep you must contact us and provide evidence that you have a licence to use the software.

Example jobs

Note the use of ${NSLOTS} in the parallel example to ensure that cores are used properly.

Serial job

Here is an example job running on 4 cores and 8GB of memory:

#$ -cwd
#$ -j y
#$ -pe smp 4
#$ -l h_rt=1:0:0
#$ -l h_vmem=2G
#$ -l avx2

module load castep/18.1-intel

castep.serial diamond

Parallel job

Here is an example job running on 96 cores across 2 ddy nodes with MPI:

#$ -cwd
#$ -j y
#$ -pe parallel 96
#$ -l infiniband=ddy-i
#$ -l h_rt=240:0:0

module load castep/18.1-intel

mpirun -np ${NSLOTS} castep.mpi hex