FCIQMC-CASPT2 with Imaginary-Time-Averaged Wave Functions.

IF 5.7 1区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Chemical Theory and Computation Pub Date : 2025-02-11 Epub Date: 2025-01-17 DOI:10.1021/acs.jctc.4c01462

Arta A Safari, Robert J Anderson, Ali Alavi, Giovanni Li Manni

引用次数: 0

Abstract

A new method to perform complete active space second-order perturbation theory on top of large active spaces optimized with full configuration quantum Monte Carlo is presented. Computing the three- and Fock-contracted four-particle density matrix from imaginary-time-averaged wave functions is found to resolve fermionic positivity violations and to ensure numerical stability. The protocol is applied to [NiFe]-hydrogenase, [Cu₂O₂]-oxidase and Fe-porphyrin model systems up to 26 electrons in 27 orbitals and benchmarked against DMRG-CASPT2.

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虚时均波函数FCIQMC-CASPT2。

提出了一种利用全组态量子蒙特卡罗优化的大活动空间上的完全活动空间二阶摄动理论的新方法。从虚时均波函数计算三粒子和福克收缩的四粒子密度矩阵，可以解决费米子正性违逆并确保数值稳定性。该方案适用于[NiFe]-氢化酶，[Cu2O2]-氧化酶和fe -卟啉模型体系，在27个轨道上有26个电子，并以DMRG-CASPT2为基准。

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Theory and Computation invites new and original contributions with the understanding that, if accepted, they will not be published elsewhere.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.