OpenMolcas¶
OpenMolcas is a quantum chemistry software package to allow an accurate treatment of very general electronic structure problems for molecular systems in both ground and excited states.
OpenMolcas is available as a module on Apocrita.
Usage¶
To run the default installed version of OpenMolcas, simply load the openmolcas
module:
$ module load openmolcas
pymolcas -h
usage: pymolcas [options] [input_file | script ...]
For full usage documentation, run pymolcas -h.
Example jobs¶
Serial job¶
Here is an example job running on 1 core and 1GB of memory:
#!/bin/bash
#SBATCH --ntasks=1 # (or -n 1) Request 1 core
#SBATCH --mem-per-cpu=1G # Request 1GB RAM per core (1GB total)
#SBATCH --time=1:0:0 # (or -t 1:0:0) Request 1 hour runtime
module load openmolcas
pymolcas example.input
Parallel job¶
Here is an example job running on 96 cores across 2 ddy nodes with MPI:
#!/bin/bash
#SBATCH --partition=parallel # (or -p parallel) Request parallel partition
#SBATCH --nodes=2 # (or -N 2) Request 2 nodes
#SBATCH --ntasks=96 # (or -n 96) Request 96 cores
#SBATCH --time=240:0:0 # (or -t 240:0:0) Request 240 hours runtime
#SBATCH --exclusive # Request exclusive compute node usage
#SBATCH --mem=0 # Book all available memory on compute nodes
module load openmolcas
# Slurm knows how many tasks to use for mpirun, detected automatically from
# ${SLURM_NTASKS}. Use -- to ensure arguments are passed to the application
# and not mpirun
pymolcas -- \
example.input