MOLCAS program system

Computer programs were MOLCAS 3 program system (25) for SCF, CASSCF, and CASPT2 calculations and the program TITAN for closed shell calculations (26). The new version of the COMENIUS program was used for open shell CCSD(T) calculations based on the spin adapted singly and doubly excited amplitudes (15, 27-29). These codes were supplemented by the generator of the no-pair hamiltonian written by B. A. Hess in all DK calculations. 

The CCSD approach has been in recent years efficiently implemented in several program systems (ACES II, CADPAC, DALTON, GAUSSIAN, MOLCAS, MOLPRO, PSI, TITAN). In particular, vectorization, exploitation of Abelian point-group symmetry, and (partial) AO-based algorithms have been used to accomplish this task. Calculations for molecules with up to ten nonhydrogen atoms... 

K. Andersson, M. R. A. Blomberg, M. Fiilscher, V. Kello, R. Lindh, P.-A. Malmquist, J. Noga, J. Olsen, B. O. Roos, A. J. Sadlej, P. E. M. Siegbahn, M. Urban and P.-O. Widmark, Molcas System of Qantum Chemistry Programs, Release 3. Theoretical Chemistry, University of Lund, Lund, Sweden and IBM Sweden (1994). 

The lOTC method was implemented in the version of the Molcas.7.3 system of programs by Slovakia Group of Quantum Chemistry (2010). Comenius University, Bratislava, Slovakia. The corresponding patches for Molcas 7.3 releases of Molcas can be obtained directly from Barysz M (E-mail temjb chem.umk.pl)... 

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