Orca - Quantum chemistry package
ORCA is a general-purpose quantum chemistry software package initiated by Frank Neese. It provides an array of quantum chemistry approaches, i.e. Hartree-Fock, (T)DFT, Møller–Plesset (MP) perturbation theory, coupled-cluster, multi-reference, semi-empirical, and multiscale methods.
Loading ORCA in your enviroment
Multiple versions of ORCA are installed at the CHPC. To have access to its latest version, you must load the appropriate modules:
module load openmpi/4.1.6-gpu
module load orca
To verify that ORCA is loaded correctly, you can use the which command:
[u0253283@notchpeak1:~]$ which orca
/uufs/chpc.utah.edu/sys/installdir/r8/orca/6.0.1/orca
Running ORCA
ORCA is a parallel program that relies on MPI. However, you do not need to use mpirun or
specify the number of tasks within the command line. Simply use:
orca inputfile >& outputfile
Examples of ORCA scripts
Examples of ORCA input files and their corresponding Slurm submission scripts can be found here.
ORCA documentation
- Within the installation:
After loading the ORCA module, navigate to$ORCA_DOC. The manual is titledmanual.pdf - Online