[1][2] The programs focus on extended multi-reference calculations of atomic and molecular ground and excited states.
In addition to standard classes of reference wave functions such as CAS and RAS, calculations can be performed with selected configurations.
Some features employ the atomic orbital integrals and gradient routines from the Dalton as well as MOLCAS program suites.
The COLUMBUS PROGRAMS were started in 1980 in the Department of Chemistry of Ohio State University by Isaiah Shavitt,[3] Hans Lischka and Ron Shepard.
Perl scripts are provided to prepare input files and to link these programs together to perform common tasks such as single point energy calculation, geometry optimization, normal mode analysis, etc.