Regensburg 2022 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 50: Frontiers of Electronic Structure Theory: Focus on Artificial Intelligence Applied to Real Materials 2

O 50.4: Vortrag

Mittwoch, 7. September 2022, 15:45–16:00, S054

All-Electron BSE@GW Method for K-Edge Core Electron Excitation Energies — •Yi Yao^1,2, Dorothea Golze^3,4, Patrick Rinke⁴, Volker Blum^2,5, and Yosuke Kanai¹ — ¹Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States — ²Thomas Lord Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708, United States — ³Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, 01062 Dresden, Germany — ⁴Department of Applied Physics, Aalto University, P.O. Box 11100, FI-00076 Aalto, Finland — ⁵Department of Chemistry, Duke University, Durham, North Carolina 27708, United States

We present an accurate computational approach to calculate K-edge core electron excitation energies, achieved by combining all-electron GW and Bethe-Salpeter equation (BSE) methods. We assess the BSE@GW approach for calculating K-edge X-ray absorption spectra using a set of small organic molecules and also a medium-sized sulfur-containing molecule, which was used in a past benchmark of an equation-of-motion coupled-cluster (EOM-CC) method by Peng and coworkers [Peng et al., J. Chem. Theory Comput., 11, 4146 (2015)]. We present the influence of different numerical approximations. We assess the basis set dependence and convergence. We identify the importance of core-correlation basis functions as well as the augmenting basis functions. Compared to the experimental values, the predicted mean absolute error by BSE@GW is as low as 0.6-0.7 eV.