Comparison of low-order multireference many-body perturbation theories

• DOI: 10.1063/1.1863912
• Publication Date: 2005-04-01T23:06:19Z
• Authors: Rajat K. Chaudhuri; Karl F. Freed; Gabriel Hose; Piotr Piecuch; Karol Kowalski; Marta Włoch; Sudip Chattopadhyay; Debashis Mukherjee; Zoltán Rolik; Ágnes Szabados; Gábor Tóth; Péter R. Surján
• Keywords: Coupled cluster; Multireference configuration interaction; Hamiltonian (control theory); Full configuration interaction

Tests have been made to benchmark and assess the relative accuracies of low-order multireference perturbation theories as compared coupled cluster (CC) full configuration interaction (FCI) methods. Test calculations include ground some excited states Be, H2,BeH2,CH2, SiH2 systems. Comparisons with FCI CC show that in most cases effective valence shell Hamiltonian (Hv) method is more accurate than other theories, although none perturbative methods approximations. We also briefly discuss basic differences among considered this work.