Spin-Symmetry Projected Constrained Unrestricted Hartree-Fock.

IF 5.7 1区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Chemical Theory and Computation Pub Date : 2025-06-10 Epub Date: 2025-05-21 DOI:10.1021/acs.jctc.5c00068

Amir Ayati, Hugh G A Burton, Stijn De Baerdemacker

引用次数: 0

Abstract

We introduce an electronic structure approach for spin-symmetry breaking and restoration at the mean-field level. The spin-projected constrained-unrestricted Hartree-Fock (SPcUHF) method restores the broken spin symmetry inherent in spin-constrained-UHF determinants by employing a nonorthogonal configuration interaction (NOCI) projection method. This method includes all possible configurations in spin space compatible with a Clebsch-Gordon recoupling scheme in a NOCI calculation. The tunable one-pair-at-a-time characteristics of the symmetry-breaking process in c-UHF allow us to reduce the computational costs of full projection. SPcUHF is tested on 4-, 6-, and 8-electron systems that exhibit dominant static and/or dynamic correlations.

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自旋对称投影约束不受限制Hartree-Fock。

我们介绍了一种在平均场水平上进行自旋对称性破缺和恢复的电子结构方法。自旋投影约束-无限制Hartree-Fock （SPcUHF）方法利用非正交组态相互作用（NOCI）投影法恢复了自旋约束-超高频决定子固有的自旋对称性破缺。该方法包含了NOCI计算中与Clebsch-Gordon重耦合方案兼容的自旋空间中所有可能的构型。c-UHF中对称破缺过程的可调谐一对一时间特性使我们能够减少全投影的计算成本。SPcUHF在4-、6-和8-电子系统上进行测试，这些系统表现出主要的静态和/或动态相关性。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Chemical Theory and Computation 化学-物理：原子、分子和化学物理

CiteScore

9.90

自引率

16.40%

发文量

568

审稿时长

1 months

期刊介绍： The Journal of Chemical Theory and Computation invites new and original contributions with the understanding that, if accepted, they will not be published elsewhere. Papers reporting new theories, methodology, and/or important applications in quantum electronic structure, molecular dynamics, and statistical mechanics are appropriate for submission to this Journal. Specific topics include advances in or applications of ab initio quantum mechanics, density functional theory, design and properties of new materials, surface science, Monte Carlo simulations, solvation models, QM/MM calculations, biomolecular structure prediction, and molecular dynamics in the broadest sense including gas-phase dynamics, ab initio dynamics, biomolecular dynamics, and protein folding. The Journal does not consider papers that are straightforward applications of known methods including DFT and molecular dynamics. The Journal favors submissions that include advances in theory or methodology with applications to compelling problems.