===== CPMD =====
----
The CPMD code is a parallelized plane wave/pseudopotential implementation of Density Functional Theory, particularly designed for ab-initio molecular dynamics.

==== Prerequisites to use CPMD on the cluster system ====

In order to use CPMD on the cluster system, you need a valid license, which is usually granted free of charge to members of academic institutions for non-profit, non-transferable personal usage after an application on their [[https://www.cpmd.org/wordpress/index.php/download/apply-for-a-license/|web site]].

After you receive your license, please let us know (''cluster-help@luis.uni-hannover.de'', please also include your user account name). We will then ask the CPMD consortium to validate your license and thereafter add you to the unix group ''cpmd'' that has access to the software.

==== Using CPMD on the cluster ====

To list all installed CPMD versions, run ''module spider cpmd''.

If you want to access CPMD version 4.3, you have to load all modules recommended by the command ''module spider CPMD/4.3'':
<code>
module load GCC/8.3.0 OpenMPI/3.1.4 CPMD/4.3
</code>

In a sample job-script below you will need to set an input file and provide the location to 
[[https://www.cpmd.org/wordpress/index.php/documentation/pseudo-potentials/|pseudo-potential]] that are available for download from CPMD website after authentication. 

<tabbox SLURM script>
<file bash cpmd-job.sh>
#!/bin/bash -l
#SBATCH --job-name=cpmd_job
#SBATCH --nodes=2
#SBATCH --ntasks-per-node=20
#SBATCH --mem=120G
#SBATCH --time=1:00:00
#SBATCH --mail-user=user@uni-hannover.de
#SBATCH --mail-type=END

# Compute node the job ran on
echo "Job ran on:" $HOSTNAME

# Load modules
module load GCC/8.3.0 OpenMPI/3.1.4 CPMD/4.3

# Change to work dir
cd $SLURM_SUBMIT_DIR
 
CPMD_INPUT=<your input file>
CPMD_OUTPUT=cpmd-job-${SLURM_JOB_ID}.log
PP_PATH=<path to the location of pseudo-potentials>

srun cpmd.x ${CPMD_INPUT} ${PP_PATH} > ${CPMD_OUTPUT}
</file>

</tabbox>

==== Further Reading ====
  * CPMD [[https://www.cpmd.org/wordpress/|home page]]
  * CPMD [[https://www.cpmd.org/wordpress/index.php/documentation/|manual]]
  * CPMD [[https://www.cpmd.org/wordpress/index.php/documentation/pseudo-potentials/|pseudo-potentials]]