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.

Access to CASTEP on CSD3
------------------------

CASTEP is free for *non-commercial* use, but does require a valid licence. Academic licences are available cost-free at `<https://licences.stfc.ac.uk/product/castep>`_.


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
    module load rhel7/default-peta4 castep

    mpirun castep problemname

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``.