C2V Insertion pathway for BeH2: A test problem for the coupled-cluster single and double excitation model

✍ Scribed by George D. Purvis III; Ron Shepard; Franklin B. Brown; Rodney J. Bartlett

• Publisher: John Wiley and Sons
• Year: 1983
• Tongue: English
• Weight: 563 KB
• Volume: 23
• Category: Article
• ISSN: 0020-7608
• DOI: 10.1002/qua.560230307

✦ Synopsis

Abstract

The coupled‐cluster single and double excitation model (CCSD) is applied to an energy path for the insertion of Be into H~2~ and compared to the full configuration interaction (FCI) and full valence–multiconfiguration self‐consistent field (FV–MCSCF) results. This model problem is a severe test of a single‐reference‐function correlated method since two configurations are heavily weighted in the FCI description. CCSD is demonstrated to describe the FCI results using a single reference function which, however, changes orbital characteristics along the sampling path. In this case CCSD gives excellent agreement with the FCI results.