Efficient random phase approximation for diradicals.

IF 3.1 2区化学 Q3 CHEMISTRY, PHYSICAL

Journal of Chemical Physics Pub Date : 2024-09-21 DOI:10.1063/5.0227556

Reza G Shirazi, Vladimir V Rybkin, Michael Marthaler, Dmitry S Golubev

引用次数: 0

Abstract

We apply the analytically solvable model of two electrons in two orbitals to diradical molecules, characterized by two unpaired electrons. The effect of doubly occupied and empty orbitals is taken into account by means of random phase approximation (RPA). We show that in the static limit, the direct RPA leads to the renormalization of the parameters of the two-orbital model. We test our model by comparing its predictions for singlet-triplet splitting with the results of several multi-reference methods for a set of thirteen molecules. We find that for this set, the static RPA results are close to those of the NEVPT2 method with two orbitals and two electrons in the active space.

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高效随机相位逼近二元化合物。

我们将可分析求解的双轨道双电子模型应用于以两个未成对电子为特征的二元分子。通过随机相近似（RPA），我们考虑到了双占轨道和空轨道的影响。我们证明，在静态极限下，直接 RPA 会导致双轨道模型参数的重正化。我们将模型对单线-三线分裂的预测结果与几种多参考方法对一组 13 种分子的预测结果进行了比较，从而检验了我们的模型。我们发现，对于这组分子，静态 RPA 的结果接近于 NEVPT2 方法的结果，即活性空间中有两个轨道和两个电子。

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 Physics 物理-物理：原子、分子和化学物理

CiteScore

7.40

自引率

15.90%

发文量

1615

审稿时长

2 months

期刊介绍： The Journal of Chemical Physics publishes quantitative and rigorous science of long-lasting value in methods and applications of chemical physics. The Journal also publishes brief Communications of significant new findings, Perspectives on the latest advances in the field, and Special Topic issues. The Journal focuses on innovative research in experimental and theoretical areas of chemical physics, including spectroscopy, dynamics, kinetics, statistical mechanics, and quantum mechanics. In addition, topical areas such as polymers, soft matter, materials, surfaces/interfaces, and systems of biological relevance are of increasing importance. Topical coverage includes: Theoretical Methods and Algorithms Advanced Experimental Techniques Atoms, Molecules, and Clusters Liquids, Glasses, and Crystals Surfaces, Interfaces, and Materials Polymers and Soft Matter Biological Molecules and Networks.