Accurate and Efficient Prediction of Double Excitation Energies Using the Particle-Particle Random Phase Approximation
Abstract
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 ()-electron state calculated by 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.
Cite
@article{arxiv.2411.16599,
title = {Accurate and Efficient Prediction of Double Excitation Energies Using the Particle-Particle Random Phase Approximation},
author = {Jincheng Yu and Jiachen Li and Tianyu Zhu and Weitao Yang},
journal= {arXiv preprint arXiv:2411.16599},
year = {2024}
}