MOLCAS

MOLCAS is an ab initio quantum chemistry software package that was developed to treat general electronic structure for molecules consisting of atoms from most of the periodic table.

MOLCAS has the primary focus of multi-configurational methods with applications typically connected to the treatment of highly degenerate states. The codes is based on a stable version of OpenMolcas. The key aspects of MOLCAS is able to work with SCF, DFT, CASSCF, RASSCF, CASPT2, and RASPT2, has a robust code, and comes with free support and updates.

The software is not primarily a commercial product and it is not sold in order to produce a fortune for its owner. It is a research product and it is used as a platform by the Lund quantum chemistry group in their work in order to develop new computational tools in quantum chemistry. The philosophy behind MOLCAS is to develop methods to allow an accurate ab-initio treatment of general electronic structure problems for molecular systems in both ground and excited states.

The tool is primarily designed to be for an educational quantum chemist, with knowledge about the different quantum chemical models in use today.