Via-Nadal Mireia, Rodríguez-Mayorga Mauricio, Ramos-Cordoba Eloy, Matito Eduard
Donostia International Physics Center (DIPC), 20018 Donostia, Euskadi, Spain.
Department of Theoretical Chemistry, VU University Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands.
J Chem Phys. 2022 May 14;156(18):184106. doi: 10.1063/5.0085284.
A natural range separation of the Coulomb hole into two components, one of them being predominant at long interelectronic separations (h ) and the other at short distances (h ), is exhaustively analyzed throughout various examples that put forward the most relevant features of this approach and how they can be used to develop efficient ways to capture electron correlation. We show that h , which only depends on the first-order reduced density matrix, can be used to identify molecules with a predominant nondynamic correlation regime and differentiate between two types of nondynamic correlation, types A and B. Through the asymptotic properties of the hole components, we explain how h can retrieve the long-range part of electron correlation. We perform an exhaustive analysis of the hydrogen molecule in a minimal basis set, dissecting the hole contributions into spin components. We also analyze the simplest molecule presenting a dispersion interaction and how h helps identify it. The study of several atoms in different spin states reveals that the Coulomb hole components distinguish correlation regimes that are not apparent from the entire hole. The results of this work hold out the promise to aid in developing new electronic structure methods that efficiently capture electron correlation.
通过各种示例对库仑空穴自然地分离为两个分量进行了详尽分析，其中一个分量在长电子间距（h）时占主导，另一个在短距离（h）时占主导。这些示例展现了该方法的最相关特征以及如何利用它们来开发捕获电子关联的有效方法。我们表明，仅依赖于一阶约化密度矩阵的h可用于识别具有主要非动态关联机制的分子，并区分两种类型的非动态关联，即A类和B类。通过空穴分量的渐近性质，我们解释了h如何获取电子关联的长程部分。我们在最小基组中对氢分子进行了详尽分析，将空穴贡献分解为自旋分量。我们还分析了呈现色散相互作用的最简单分子以及h如何有助于识别它。对处于不同自旋状态的几个原子的研究表明，库仑空穴分量区分了从整个空穴中不明显的关联机制。这项工作的结果有望有助于开发有效捕获电子关联的新电子结构方法。
