Valence universal exponential ansatz and the cluster structure of multireference configuration interaction wave function
Valence universal exponential ansatz and the cluster structure of multireference configuration interaction wave function
复制标题
价普适指数模拟与多参考构型相互作用波函数的簇结构
DOI：
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发表时间：
1989
期刊：
影响因子：
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通讯作者：
J. Paldus
中科院分区：
文献类型：
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作者：
B. Jeziorski;J. Paldus
给出了开壳耦合簇理论的一个严格的代数表述。该公式给出了显示开壳簇振幅与多参考CI波函数线性系数之间关系的显式公式。当使用价泛指数函数时，具有n个价电子的态的CI系数对n -体和高阶簇算符有贡献。研究了要求四体星团振幅较小的星团条件的含义。结果表明，对于价普遍理论，这些条件导致了涉及电子数不同的系统状态的CI系数的近似关系。对于Lindgren’s ansatz，这些关系在电子数最大的状态对应的CI系数中是线性的。对于Jeziorski和Monkhorst的价-非泛指数ansatz，对于el数不同的系统，聚类条件不会混合波函数。
A rigorous algebraic formulation of open‐shell coupled‐cluster theory is presented. This formulation yields explicit formulas exhibiting the relationship between open‐shell cluster amplitudes and linear coefficients of multireference CI wave functions. When the valence‐universal exponential ansatz is used, the CI coefficients of states with n valence electrons contribute to the n‐body and higher‐order cluster operators. The implications of cluster conditions, requiring that the four‐body cluster amplitudes be small, are investigated. It is shown that for valence‐universal theories these conditions lead to approximate relations involving CI coefficients for states of systems differing in the number of electrons. For Lindgren’s ansatz these relations are linear in the CI coefficients corresponding to states with the largest electron number. For the valence‐nonuniversal exponential ansatz of Jeziorski and Monkhorst, the cluster conditions do not mix wave functions for systems which differ in the number of el...