• Versions: 4.2.0 and 4.1.2
• Parallelization: process level (OpenMPI)

Generic reference for ORCA:

Neese, F. “The ORCA program system” Wiley Interdisciplinary Reviews: Computational Molecular Science, 2012, Vol. 2, Issue 1, Pages 73–78.  

For ORCA 4.0 and higher, additionally:

Neese, F. “Software update: the ORCA program system, version 4.0” Wiley Interdisciplinary Reviews: Computational Molecular Science, 2017, Vol. 8, Issue 1, p. e1327.

Please also have a look at the following authoritative documents:
/home/units/Fak_II/chemie/orca/4.2.0/orca4.2-eula.pdf and /home/units/Fak_II/chemie/orca/4.2.0/Third_Party_Licenses_ORCA_4.2.pdf.

Remark:
Using specific methods included in SOFTWARE may require citing additional articles, as described in the manual. LICENSEE agrees to honor the request to cite additional papers as appropriate.

1) Loading module:

module use /home/units/Fak_II/chemie/modules
module add chemistry/orca/4.2.0

2) Running:

• In serial mode:

   orca [name_of_input_file]

• In parallel mode:

   srun --hint=nomultithread -n1 -E orca [name_of_input_file]

• In parallel mode, there is a bug in ORCA that defends a user to run more than one job on the same node. This problem seems to be unfixable. (No help in ORCA forum available).

• For parallel runs: Batch jobs with ORCA