Bethe-Salpeter Equation Calculations of Core Excitation Spectra
Eric L. Shirley, Vinson T. John, John J. Rehr, Joshua J. Kas
We present a hybrid approach for GW/Bethe-Salpeter Equation (BSE) calculations of core excitation spectra, including x-ray absorption (XAS), electron energy loss spectra (EELS), and nonresonant inelastic x-ray scattering (NRIXS). The method is based on ab initio wavefunctions from the plane-wave pseudopotential code ABINIT; atomic core-level states and projector augmented wave (PAW) transition matrix elements; the NIST core-level BSE solver; and a many-pole GW self-energy model to account for final-state broadening and self-energy shifts. Multiplet effects are also accounted for. The approach is implemented using an interface dubbed OCEAN (Obtaining Core Excitations using BINIT and NBSE). As examples of calculations, we present results for LiF including the K-edge XAS and NRIXS, the K-edges of KCl, and the multiplet spectrum in the Ti L2,3-edge in SrTiO3, and are compared with experiment and with other theoretical approaches.
, John, V.
, Rehr, J.
and Kas, J.
Bethe-Salpeter Equation Calculations of Core Excitation Spectra, Physical Review B, [online], https://doi.org/10.1103/PhysRevB.83.115106
(Accessed December 10, 2023)