TY - JOUR T1 - Intermediate hamiltonian hilbert space coupled cluster method: theory and pilot application JF - International Journal of Quantum Chemistry Y1 - 2009 A1 - Eliav, Ephraim A1 - Borschevsky, Anastasia A1 - Shamasundar, K. R. A1 - Pal, Sourav A1 - Kaldor, Uzi KW - coupled cluster KW - Hilbert space KW - intermediate Hamiltonian AB -

The intermediate Hamiltonian state universal (Hilbert-space) coupled-cluster method is presented, using a formalism similar to that developed for the valence universal (Fock-space) approach. The method is expected to be applicable to many states not accessible by traditional multiroot multireference all-order size-extensive approaches. A pilot application to excited states of atomic beryllium shows good convergence and agreement with experiment and full CI values. (C) 2009 Wiley Periodicals, Inc. Int J Quantum Chem 109: 2909-2915, 2009

PB - JOHN WILEY & SONS INC CY - 111 RIVER ST, HOBOKEN, NJ 07030 USA VL - 109 IS - 13 U3 - Foreign U4 - 1.302 ER -