A coupled cluster approach with excitations up to six orbital pairs: The formulation and test applications for bond breaking processes

作者：Xu Enhua; Kou Zhuangfei; Li Shuhua^*

来源：Journal of Chemical Physics, 2011, 134(23): 234104.

DOI：10.1063/1.3600396

The formalism of the coupled cluster (CC) method with excitations up to six orbital pairs (CC6P) and its illustrative applications are presented. By definition, CC6P includes connected excitations from full singles, doubles, triples, and partial quadruples, pentuples, and hextuples. CC6P and its approximate variants (CC6P-4, CC6P-5, and CC6P-6a) have the similar computational cost as the CC singles, doubles, and triples (CCSDT). They have been applied to investigate the potential energy surfaces for bond dissociation processes in four small molecules (F(2), H(2)O, N(2), and F(2)(+)). In comparison with full configuration interaction results, CC6P and its approximate variants are demonstrated to provide very accurate descriptions for the single-bond breaking process in F(2). While for multi-bond breaking processes, these methods provide considerable improvement over CCSDT.

• 出版日期2011-6-21
• 单位南京大学