Purpose: electronic Structure Calculations
Latest version: 5.0.4
License: (tick) Free of use for academics
                 Mixed
Website: https://orcaforum.kofo.mpg.de/_ext-link

ORCA is a program that implements HF, DFT, semi-empirical, and high level ab initio (CI and CC) methods with gaussian basis sets for electronic structure calculations.

ORCA implements a variety of standard quantum chemistry methods, but is especially tailored at geometry optimisation and prediction of spectroscopic parameters in open-shell molecular systems. It can be coupled to Gromacs for QM/MM calculations.

SLURM Submit script example

For more information use the Job Script Generator.


orca_example.slm
#!/bin/bash
#SBATCH -J orca_example
#SBATCH -e orca_example.err
#SBATCH -o orca_example.out
#SBATCH -p std
#SBATCH --ntasks=4
#SBATCH -t 02-00:00

module load apps/orca/4.1.0

##
#  Modify the input and output files!
INPUT_FILE=orca_example.inp
OUTPUT_FILE=orca_example.out
 
##
#  You don't need to modify nothing more
cp -r ${SLURM_SUBMIT_DIR}/${INPUT_FILE} ${SCRATCH}
cd ${SCRATCH}
 
$(which orca) ${INPUT_FILE} > ${OUTPUT_FILE}
 
cp ./${OUTPUT_FILE} ${SLURM_SUBMIT_DIR}

Sbatch options:

The options shown in the example are detailed below. For more information and a more comprehensive list of available options, see the sbatch command page.

  • -J: Name for the job's allocation.
  • -e: Name of the stderr redirection filename.
  • -o: Name of the stdout redirection filename.
  • -p: Name of the partition (queue) where the job will be submitted.

    • For parallel calculations, the number of processes must be explicitly indicated in orca_example.inp file using:

      %pal nprocs 4 end

  • -n: Number of tasks.

  • -c: Number of cores per task.
  • -t: Set the job's time limit. If the job don't finish before the time runs out, it will be killed.

Software execution information:

ORCA uses 3000MB per core by default. This value can be changed in orca_example.inp using the directive:

%maxcore 3000 end

It is recommended to use ~75% of the requested memory to SLURM, which is 3990 MB per core.



  • No labels