多组态微扰理论中的广义莫勒-普莱塞特微扰项划分

Generalized Møller-Plesset Partitioning in Multiconfiguration Perturbation Theory.

作者信息

Kobayashi Masato, Szabados Ágnes, Nakai Hiromi, Surján Péter R

机构信息

Laboratory of Theoretical Chemistry, Institute of Chemistry, Eötvös University, H1518 Budapest POB 32, Hungary, Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, Tokyo 169-8555, Japan, Department of Theoretical and Computational Molecular Science, Institute for Molecular Science, Okazaki 444-8585, Japan, and Research Institute for Science and Engineering (RISE), Waseda University, Tokyo 169-8555, Japan.

出版信息

J Chem Theory Comput. 2010 Jul 13;6(7):2024-33. doi: 10.1021/ct1001939. Epub 2010 Jun 17.

DOI:10.1021/ct1001939

PMID:26615931

Abstract

Two perturbation (PT) theories are developed starting from a multiconfiguration (MC) zero-order function. To span the configuration space, the theories employ biorthogonal vector sets introduced in the MCPT framework. At odds with previous formulations, the present construction operates with the full Fockian corresponding to a principal determinant, giving rise to a nondiagonal matrix of the zero-order resolvent. The theories provide a simple, generalized Møller-Plesset (MP) second-order correction to improve any reference function, corresponding either to a complete or incomplete model space. Computational demand of the procedure is determined by the iterative inversion of the Fockian, similarly to the single reference MP theory calculated in a localized basis. Relation of the theory to existing multireference (MR) PT formalisms is discussed. The performance of the present theories is assessed by adopting the antisymmetric product of strongly orthogonal geminal (APSG) wave functions as the reference function.

摘要

从多组态（MC）零阶函数出发，发展了两种微扰（PT）理论。为了跨越组态空间，这些理论采用了在多组态微扰理论（MCPT）框架中引入的双正交向量集。与之前的公式不同，当前的构建使用与主行列式相对应的完整福克矩阵，从而产生零阶预解式的非对角矩阵。这些理论提供了一种简单的、广义的莫勒-普列斯特定理（MP）二阶修正，以改进任何参考函数，该参考函数对应于完整或不完整的模型空间。该过程的计算需求由福克矩阵的迭代求逆确定，这与在定域基中计算的单参考MP理论类似。讨论了该理论与现有多参考（MR）PT形式体系的关系。通过采用强正交双电子对（APSG）波函数的反对称积作为参考函数，评估了当前理论的性能。