Publications [#376277] of Weitao Yang

Journal Articles

1. Li, J; Jin, Y; Yu, J; Yang, W; Zhu, T, Accurate Excitation Energies of Point Defects from Fast Particle-Particle Random Phase Approximation Calculations., The journal of physical chemistry letters, vol. 15 no. 10 (March, 2024), pp. 2757-2764 [doi]
   (last updated on 2025/02/02)

   Abstract:
   We present an efficient particle-particle random phase approximation (ppRPA) approach that predicts accurate excitation energies of point defects, including the nitrogen-vacancy (NV^-) and silicon-vacancy (SiV⁰) centers in diamond and the divacancy center (VV⁰) in 4H silicon carbide, with errors of ±0.2 eV compared with experimental values. Starting from the (N + 2)-electron ground state calculated with density functional theory (DFT), the ppRPA excitation energies of the N-electron system are calculated as the differences between the two-electron removal energies of the (N + 2)-electron system. We demonstrate that the ppRPA excitation energies converge rapidly with a few hundred canonical active-space orbitals. We also show that active-space ppRPA has weak DFT starting-point dependence and is significantly cheaper than the corresponding ground-state DFT calculation. This work establishes ppRPA as an accurate and low-cost tool for investigating excited-state properties of point defects and opens up new opportunities for applications of ppRPA to periodic bulk materials.