A Comparison of Two Methods for Selecting Vibrational Configuration Interaction Spaces on a Heptatomic System: Ethylene Oxyde

Didier Bégué (1) , Neil Gohaud (1) , Claude Pouchan (1) , Patrick Cassam-Chenaï (2) , Jacques Liévin (3)

1 IPREM - Institut pluridisciplinaire de recherche sur l'environnement et les matériaux
2 JAD - Laboratoire Jean Alexandre Dieudonné
3 Service de Chimie Quantique et Photophysique

Two recently developed methods for solving the molecular vibrational Schrödinger equation, namely, the parallel vibrational multiple window configuration interaction (P-VMWCI) and the vibrational mean field configuration interaction (VMFCI), are presented and compared on the same potential energy surface of ethylene oxide, c-C2H4O. It is demonstrated on this heptatomic system with strong resonances that both approaches converge towards the same fundamental frequencies. This confirms their ability to tackle the vibrational problem of large molecules for which full configuration interaction calculations are not tractable.

Domaines: Chimie théorique et/ou physique

Didier Bégué, Neil Gohaud, Claude Pouchan, Patrick Cassam-Chenaï, Jacques Liévin. A Comparison of Two Methods for Selecting Vibrational Configuration Interaction Spaces on a Heptatomic System: Ethylene Oxyde. Journal of Chemical Physics, 2007, 127, http://dx.doi.org/10.1063/1.2795711. ⟨10.1063/1.2795711⟩. ⟨hal-00151806⟩