Accurate and Efficient Prediction of Double Excitation Energies Using the Particle-Particle Random Phase Approximation

Fuente: arXiv
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Main Authors: Yu, Jincheng, Li, Jiachen, Zhu, Tianyu, Yang, Weitao
Format: Preprint
Published: 2024
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author Yu, Jincheng
Li, Jiachen
Zhu, Tianyu
Yang, Weitao
author_facet Yu, Jincheng
Li, Jiachen
Zhu, Tianyu
Yang, Weitao
contents Double excitations are crucial to understanding numerous chemical, physical, and biological processes, but accurately predicting them remains a challenge. In this work, we explore the particle-particle random phase approximation (ppRPA) as an efficient and accurate approach for computing double excitation energies. We benchmark ppRPA using various exchange-correlation functionals for 21 molecular systems and two point defect systems. Our results show that ppRPA with functionals containing appropriate amounts of exact exchange provides accuracy comparable to high-level wave function methods such as CCSDT and CASPT2, with significantly reduced computational cost. Furthermore, we demonstrate the use of ppRPA starting from an excited ($N-2$)-electron state calculated by $Δ$SCF for the first time, as well as its application to double excitations in bulk periodic systems. These findings suggest that ppRPA is a promising tool for the efficient calculation of double and partial double excitation energies in both molecular and bulk systems.
format Preprint
id arxiv_https___arxiv_org_abs_2411_16599
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Accurate and Efficient Prediction of Double Excitation Energies Using the Particle-Particle Random Phase Approximation
Yu, Jincheng
Li, Jiachen
Zhu, Tianyu
Yang, Weitao
Chemical Physics
Double excitations are crucial to understanding numerous chemical, physical, and biological processes, but accurately predicting them remains a challenge. In this work, we explore the particle-particle random phase approximation (ppRPA) as an efficient and accurate approach for computing double excitation energies. We benchmark ppRPA using various exchange-correlation functionals for 21 molecular systems and two point defect systems. Our results show that ppRPA with functionals containing appropriate amounts of exact exchange provides accuracy comparable to high-level wave function methods such as CCSDT and CASPT2, with significantly reduced computational cost. Furthermore, we demonstrate the use of ppRPA starting from an excited ($N-2$)-electron state calculated by $Δ$SCF for the first time, as well as its application to double excitations in bulk periodic systems. These findings suggest that ppRPA is a promising tool for the efficient calculation of double and partial double excitation energies in both molecular and bulk systems.
title Accurate and Efficient Prediction of Double Excitation Energies Using the Particle-Particle Random Phase Approximation
topic Chemical Physics
url https://arxiv.org/abs/2411.16599