ORCA is a modern electronic structure program package written by Frank Neese, with contributions from many current and former coworkers and several collaborating groups. The binaries of ORCA are available free of charge for academic users for a variety of platforms.

ORCA is a flexible, efficient and easy-to-use general purpose tool for quantum chemistry with specific emphasis on spectroscopic properties of open-shell molecules. It features a wide variety of standard quantum chemical methods ranging from semiempirical methods to DFT to single- and multireference correlated ab initio methods. It can also treat environmental and relativistic effects.

Due to the user-friendly style, ORCA is considered to be a helpful tool not only for computational chemists, but also for chemists, physicists and biologists that are interested in developing the full information content of their experimental data with help of calculations.

Website https://orcaforum.cec.mpg.de
Licenses Other (Not Open)
Categories Computational Chemistry
Software Requirements -
Hardware Requirements -
Platforms Mac OS Linux Windows
Languages C++
Input Formats There are no input formats associated to this software.
Output Formats There are no output formats associated to this software.
Diamond Light Source

To use ORCA you must load the corresponding module:

> module load orca

This currently loads version ORCA 3.0.3. Due to changes in the ORCA license, we are currently unable to upgrade to the latest release series 4.x.

After executing the module load command, ORCA's executable will be added to the PATH environment variable.


The same procedure can be used to load ORCA on the rnice cluster. The 4.x release series is also available.

Documentation / Tutorials
There are no tutorials or documentation for this software.

(1) Neese, F. Wiley Interdisciplinary Reviews: Computational Molecular Science 2012, 2 (1), 73. (2) Neese, F. Wiley Interdisciplinary Reviews: Computational Molecular Science 2018, 8 (1), e1327.

Instruments This software is not associated to any instruments.
No screenshots have been uploaded for this software.
No example datasets have been uploaded for this software.