MOLCAS

MOLCAS allows an accurate ab initio treatment of very general electronic structure problems for molecular systems in both ground and excited states. MOLCAS contains a number of codes that can perform such calculations (MP2, CC, CPF, CCSD(T) etc.). It can also treat highly degenerate states using general and effective multiconfigurational SCF calculations at the CASSCF level, as well as RASSCF.