Accurate Prediction of Core Level Binding Energies from Ground-State Density Functional Calculations: The Importance of Localization and Screening

TL;DR

This paper introduces a new method that combines localization and screening effects to accurately predict core level binding energies from ground-state density functional calculations, aiding interpretation of spectroscopic data.

Contribution

The work develops a novel approach integrating localization procedures and screening effects to improve CLBE predictions from density functional theory.

Findings

Accurately predicts CLBEs using the combined method.

Addresses delocalization issues in conventional density functional approximations.

Provides insights into electronic structure and chemical environment analysis.

Abstract

A new method for predicting core level binding energies (CLBEs) is developed by both localizing the core-level states and describing the screening effect. CLBEs contain important information about the electronic structure, elemental chemistry, and chemical environment of molecules and materials. Theoretical study of CLBEs can provide insights for analyzing and interpreting the experimental results obtained from the X-ray photoelectron spectroscopy, in which the overlapping of signals is very common. The localization of core-level holes is important for the theoretical calculation of CLBEs. Predicting CLBEs from commonly used density functional approximations (DFAs) is challenging, because conventional DFAs often produce delocalized core-level states, especially when degenerate core-level states exist. In this work, we combine the localization procedure from the localized orbital scaling correction method and the curvature matrix generalized from the exact second-order correction method that contains the screening effect, and the resulting approach can accurately predict CLBEs from ground-state density functional calculations.