Work

Particle–Particle Random Phase Approximation for Predicting Correlated Excited States of Point Defects

Year: 2024

Type: article

Abstract: The particle–particle random phase approximation (ppRPA) within the hole–hole channel was recently proposed as an efficient tool for computing excitation energies of point defects in solids [ J. Phys. Chem. Lett. 2024, 15, 2757–2764]. In this work, we investigate the application of ppRPA within the particle–particle channel for predicting correlated excited states of point defects, including the carbon-vacancy (VC) in diamond, the oxygen-vacancy (VO) in magnesium oxide (MgO), and the carbon dimer defect (C B C N ) in two-dimensional hexagonal boron nitride (h-BN). Starting from a density functional theory calculation of the ( N – 2)-electron ground state, vertical excitation energies of the N -electron system are obtained as the differences between the two-electron addition energies. We show that active-space ppRPA with the B3LYP functional yields accurate excitation energies, with errors mostly smaller than 0.1 eV for tested systems compared to available experimental values. We further develop a natural transition orbital scheme within ppRPA, which provides insights into the multireference character of defect states. This study, together with our previous work, establishes ppRPA as a low-cost and accurate method for investigating excited-state properties of point defect systems.

Source: Journal of Chemical Theory and Computation

DOI: 10.1021/acs.jctc.4c00829

Authors: Jiachen Li, Yu Jin, Jincheng Yu, Weitao Yang, Tianyu Zhu

Institutions: Yale University, University of Chicago, Duke University

Language: English

Topic: Advanced Chemical Physics Studies

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green