Generalized valence bond wave functions in quantum Monte Carlo

被引：30

作者：

Anderson, Amos G. ^{[1
]}

Goddard, William A., III ^{[1
]}

机构：

[1] CALTECH, Mat & Proc Simulat Ctr, Div Chem & Chem Engn, Pasadena, CA 91125 USA

来源：

JOURNAL OF CHEMICAL PHYSICS | 2010年 / 132卷 / 16期

关键词：

BERYLLIUM DIMER; GROUND-STATE; AB-INITIO; TRIPLET ETHYLENE; EXCITED-STATES; METHYLENE CH2; BASIS-SETS; MOLECULES; CHEMISTRY; TRANSITIONS;

D O I：

10.1063/1.3377091

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：

We present a technique for using quantum Monte Carlo (QMC) to obtain high quality energy differences. We use generalized valence bond (GVB) wave functions, for an intuitive approach to capturing the important sources of static correlation, without needing to optimize the orbitals with QMC. Using our modifications to Walker branching and Jastrows, we can then reliably use diffusion quantum Monte Carlo to add in all the dynamic correlation. This simple approach is easily accurate to within a few tenths of a kcal/mol for a variety of problems, which we demonstrate for the adiabatic singlet-triplet splitting in methylene, the vertical and adiabatic singlet-triplet splitting in ethylene, 2+2 cycloaddition, and Be(2) bond breaking. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3377091]

引用

页数：13

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