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Orca is an ab initio quantum chemistry program package for 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 available as a module on Apocrita.


To run the default installed version of Orca, simply load the orca module:

$ module load orca

orca <input-file> > <out-file>

For usage documentation, click here.

Example job

Serial job

Here is an example job running on 1 core and 1GB of memory:

#$ -cwd
#$ -j y
#$ -pe smp 1
#$ -l h_rt=1:0:0
#$ -l h_vmem=1G

module load orca

orca mywater.inp > mywater.out