2022 Volume 65 Issue 5 Pages 236-241
We present a first-principles method based on density functional theory (DFT) to calculate the absolute binding energy of core electrons with high accuracy. The method is based on DFT for the constrained “ground state” based on the Gunnarsson-Lundqvist (GL) theorem, and introduces the penalty functional method and the exact Coulomb cutoff method to perform the calculation of the final state. The average absolute error for 26 cases of solids and molecules is 0.42 eV and the relative error is 0.17%. We present applications to silicene and borophene, and show that the results can be directly compared with the binding energies obtained by X-ray photoelectron spectroscopy.
