HILBERT-SPACE COUPLED-CLUSTER METHOD IN AN INCOMPLETE MODEL SPACE

被引：47

作者：

BERKOVIC, S ^{[1
]}

KALDOR, U ^{[1
]}

机构：

[1] TEL AVIV UNIV,SCH CHEM,IL-69978 TEL AVIV,ISRAEL

来源：

CHEMICAL PHYSICS LETTERS | 1992年 / 199卷 / 1-2期

关键词：

D O I：

10.1016/0009-2614(92)80046-E

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The Hilbert space multireference coupled-cluster method with single and double excitations (HS-MRCCSD) is implemented in complete and special classes of incomplete model spaces. Vertical excitation energies of the water molecule are calculated. Good agreement (within 0.1 eV) is obtained with experimental values, and also with results of Fock space calculations which include effects of triple excitations in lowest order (FS-MRCCSD+T). The HS-MRCCSD functions are not pure spin states, and small energy differences occur between sublevels which should be degenerate.

引用

页码：42 / 46

页数：5

共 73 条

[1] ORTHOGONALLY-SPIN-ADAPTED COUPLED-CLUSTER THEORY FOR CLOSED-SHELL SYSTEMS INCLUDING TRI-EXCITED CLUSTERS [J].