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ORCA

ORCA is an ab initio quantum chemistry program package that contains modern electronic structure methods including density functional theory, many-body perturbation, coupled cluster, multireference methods, and semi-empirical quantum chemistry methods. Its main field of application is larger molecules, transition metal complexes, and their spectroscopic properties. ORCA is developed in the research group of Frank Neese. The free version is available only for academic use at academic institutions.

Available

  • Puhti: 6.0.0
  • Mahti: 6.0.0

Note that due to licensing issues every user has to install their own copy of the program.

License

ORCA users should register, agree to the EULA , download and install a private copy of the program (via the ORCA forum website). The free version is available only for academic use at academic institutions.

Usage

  • Download the ORCA 6.0.0, Linux, x86-64, shared-version,orca_6_0_0_linux_x86-64_avx2_shared_openmpi416.tar.xz
  • Move the downloaded file to your computing project's application area (/projappl/<proj>) on Puhti
  • Unpack the package, tar xf orca_6_0_0_linux_x86-64_avx2_shared_openmpi416.tar.xz

Example batch scripts

Note

Wave function-based correlations methods, both single and multireference, often create a substantial amount of disk I/O. In order to achieve maximal performance for the job and to avoid excess load on the Lustre parallel file system it is advisable to use the local disk.

#!/bin/bash
#SBATCH --partition=test
#SBATCH --nodes=2
#SBATCH --ntasks-per-node=40      # MPI tasks per node
#SBATCH --account=yourproject     # insert here the project to be billed 
#SBATCH --time=00:15:00           # time as `hh:mm:ss`
module purge
module load gcc/11.3.0 openmpi/4.1.4 intel-oneapi-mkl/2022.1.0
export ORCADIR=<path to your ORCA directory>/orca_6_0_0_shared_openmpi416_avx2/
export LD_LIBRARY_PATH=${ORCADIR}:${LD_LIBRARY_PATH}

# Set $ORCA_TMPDIR to point to the submission directory
export ORCA_TMPDIR=$SLURM_SUBMIT_DIR
# create an mpirun script that executes srun
echo exec 'srun $(echo "${@}" | sed 's/^-np/-n/')' >./mpirun
chmod +x ./mpirun
touch Jobid_is_$SLURM_JOB_ID 

${ORCADIR}/orca orca6.inp > orca6.out
rm -f  ${SLURM_SUBMIT_DIR}/mpirun

#!/bin/bash
#SBATCH --partition=large
#SBATCH --nodes=2
#SBATCH --ntasks-per-node=40
#SBATCH --account=yourproject     # insert here the project to be billed
#SBATCH --time=00:15:00           # time as `hh:mm:ss`
#SBATCH --gres=nvme:100  # requested local disk space in GB
module purge
module load gcc/11.3.0 openmpi/4.1.4 intel-oneapi-mkl/2022.1.0
export ORCADIR=<path to your ORCA directory>/orca_6_0_0_shared_openmpi416_avx2/
export LD_LIBRARY_PATH=${ORCADIR}:${LD_LIBRARY_PATH}

# create a mpirun script that executes srun
echo exec 'srun $(echo "${@}" | sed 's/^-np/-n/')' >./mpirun
chmod +x ./mpirun
export PATH=${SLURM_SUBMIT_DIR}:${PATH}
touch Jobid_is_$SLURM_JOB_ID 


#Set $ORCA_TMPDIR to point to the local disk
export ORCA_TMPDIR=$LOCAL_SCRATCH
# Copy only necessary files to $ORCA_TMPDIR
cp $SLURM_SUBMIT_DIR/*.inp $ORCA_TMPDIR/
# Move to $ORCA_TMPDIR
cd $ORCA_TMPDIR

$ORCADIR/orca orca6.inp > ${SLURM_SUBMIT_DIR}/orca6.out
rm -f  ${SLURM_SUBMIT_DIR}/mpirun
# Copy all output to submit directory
cp -r $ORCA_TMPDIR $SLURM_SUBMIT_DIR

#!/bin/bash
#SBATCH --partition=test
#SBATCH --nodes=1
#SBATCH --ntasks-per-node=128
#SBATCH --account=yourproject     # insert here the project to be billed
#SBATCH --time=0:10:00 # time as hh:mm:ss
module purge
module load gcc/11.2.0 openmpi/4.1.2 openblas/0.3.18-omp
export ORCADIR=<path to your ORCA directory>/orca_6_0_0_shared_openmpi416_avx2/
export LD_LIBRARY_PATH=${ORCADIR}:${LD_LIBRARY_PATH}

# create a mpirun script that executes srun
echo exec 'srun $(echo "${@}" | sed 's/^-np/-n/')' >./mpirun
chmod +x ./mpirun
export PATH=${SLURM_SUBMIT_DIR}:${PATH}
touch Jobid_is_$SLURM_JOB_ID

${ORCADIR}/orca orca6.inp > orca6.out
rm -f  ${SLURM_SUBMIT_DIR}/mpirun

Note

Please remember to adjust %pal nproc in your input file according to the total number of requested MPI tasks (--nodes * --ntasks-per-node).

References

The generic references for ORCA are:

Please do not only cite the above generic reference, but also cite in addition the original papers that report the development and ORCA implementation of the methods you have used in your studies! The publications that describe the functionality implemented in ORCA are given in the manual.

More information