期刊
MOLECULAR PHYSICS
卷 108, 期 21-23, 页码 3091-3103出版社
TAYLOR & FRANCIS LTD
DOI: 10.1080/00268976.2010.522206
关键词
correlation energy; explicitly correlated functions; Gaussian geminals; coupled-cluster method; strong orthogonality
资金
- National Science Foundation [CHE-0848589]
Explicitly correlated functions have been used since 1929, but initially only for two-electron systems. In 1960, Boys and Singer showed that if the correlating factor is of Gaussian form, many-electron integrals can be computed for general molecules. The capability of explicitly correlated Gaussian (ECG) functions to accurately describe many-electron atoms and molecules was demonstrated only in the early 1980s when Monkhorst, Zabolitzky and the present authors cast the many-body perturbation theory (MBPT) and coupled cluster (CC) equations as a system of integro-differential equations and developed techniques of solving these equations with two-electron ECG functions (Gaussian-type geminals, GTG). This work brought a new accuracy standard to MBPT/CC calculations. In 1985, Kutzelnigg suggested that the linear r12 correlating factor can also be employed if n-electron integrals, n 2, are factorised with the resolution of identity. Later, this factor was replaced by more general functions f (r12), most often by [image omitted], usually represented as linear combinations of Gaussian functions which makes the resulting approach (called F12) a special case of the original GTG expansion. The current state-of-art is that, for few-electron molecules, ECGs provide more accurate results than any other basis available, but for larger systems the F12 approach is the method of choice, giving significant improvements over orbital calculations.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据