Molcas 8.2

Molcas is an ab initio quantum chemistry software package developed by scientists to be used by scientists. The basic philosophy is is to be able to treat general electronic structures for molecules consisting of atoms from most of the periodic table. As such, the primary focus of the package is on multiconfigurational methods with applications typically connected to the treatment of highly degenerate states.

Starting from the release of Molcas 8.4 (expected at Dec. 2018), Molcas code will be based on a stable version of OpenMolcas. In contrary to Molcas, which comes with support and verified release, OpenMolcas is a developer version, which is written by developers community.

Key aspects of Molcas:

  • Fast, accurate, and robust code
  • Free support and updates
Molcas is not a black box tool. The user should be an educated quantum chemist, with some knowledge about the different quantum chemical models in use today, their application areas and their inherent accuracy. The MOLCAS group arranges regular MOLCAS workshops, which teaches how to use the software.

About Documentation
Download Community


  • 170808 Molcas 8.2 Revision 170808 is available!
    Molcas 8 users (with a valid licence) can download binaries for Molcas 8.2 using the access to User area. To obtain the source code, send e-mail to
    Note! if you already have Molcas 8.2: the difference is bug fixing in installation, and update for ANISO codes. Most probably you do not need the update from Molcas 8.2 Rev. 170401.
  • 160919 New book Multiconfigurational Quantum Chemistry
  • If you would like to join Molcas developer's team, submit your project here.