Core-Ionized States and X-ray Photoelectron Spectra of Solids From Periodic Algebraic Diagrammatic Construction Theory

TL;DR

This paper introduces the first implementation of periodic algebraic diagrammatic construction theory (ADC) for core-ionized states and X-ray photoelectron spectra in solids, demonstrating its accuracy and potential for material analysis.

Contribution

It presents the first implementation and benchmarking of periodic ADC for core-ionized states in solids, showing promising accuracy and insights into satellite features.

Findings

ADC(2) and ADC(2)-X predict core ionization energies within ~1.5 and 0.5 eV of experiments.

ADC(2)-X captures satellite features in XPS spectra, overestimating their energies.

Satellite transitions involve strong configuration interaction with delocalized orbitals.

Abstract

We present the first-ever implementation and benchmark of periodic algebraic diagrammatic construction theory (ADC) for core-ionized states and X-ray photoelectron spectra (XPS) in crystalline materials. Using a triple-zeta Gaussian basis set and accounting for finite-size and scalar relativistic effects, the strict and extended second-order ADC approximations (ADC(2) and ADC(2)-X) predict the core ionization energies of weakly correlated solids within ~ 1.5 and 0.5 eV of experimental measurements, respectively. We further demonstrate that the ADC(2)-X method can capture the satellite features in XPS spectra of graphite, cubic and hexagonal boron nitride, and TiO2, albeit significantly overestimating their energies. The ADC(2)-X calculations reveal that the satellite transitions display strong configuration interaction with excitations involving several frontier orbitals delocalized in phase space. Our work demonstrates that ADC is a promising first-principles approach for simulating the core-excited states and X-ray spectra of materials, highlighting its potential and motivating further development.