Theoretical calculation of finite-temperature X-ray absorption fine structure: application to sodium K-edge in NaCl

Abstract

We present a comprehensive computational framework for reproducing the full X-ray absorption fine structure (XAFS) through quantum-chemical simulations. The near-edge region is accurately captured using an efficient implementation of time-dependent density-functional perturbation theory applied to core excitations, while ab initio molecular dynamics provides essential sampling of core-excitation energies and interatomic distance distributions for interpreting extended X-ray absorption fine structure (EXAFS) features. Owing to the efficiency of the approach, the total spectrum can be decomposed into contributions from bulk, defective, and surface environments, which commonly coexist in experimental systems. The methodology is demonstrated for sodium at the Na K-edge in NaCl, where the predicted spectra show good agreement with experimental measurements on thin film samples. This strategy offers a practical route to generating chemically specific XAFS cross-section data for elements and species that remain challenging to characterize experimentally, thereby enabling deeper insights into materials of technological importance.

References in corpus (9)

• Canonical sampling through velocity-rescaling
• Separable Dual Space Gaussian Pseudo-potentials
• Relativistic separable dual-space Gaussian Pseudopotentials from H to Rn
• CP2K: An Electronic Structure and Molecular Dynamics Software Package -- Quickstep: Efficient and Accurate Electronic Structure Calculations
• Bethe-Salpeter Equation Calculations of Core Excitation Spectra
• Highly Accurate Prediction of Core Spectra of Molecules at Density Functional Theory Cost: Attaining sub eV Error from a Restricted Open-Shell Kohn-Sham Approach
• Cubic boron nitride: an experimental and theoretical ELNES study
• First principles correction scheme for linear-response time-dependent density functional theory calculations of core electronic states
• Simulating Transient X-ray Photoelectron Spectra of Fe(CO)5 and Its Photodissociation Products With Multireference Algebraic Diagrammatic Construction Theory