An Assessment of Different Electronic Structure Approaches for Modeling Time-Resolved X-ray Absorption Spectroscopy

TL;DR

This paper evaluates various electronic structure methods for accurately simulating time-resolved X-ray absorption spectra, providing guidance on method selection for different molecular systems.

Contribution

It compares multiple protocols, including coupled-cluster and DFT approaches, for modeling excited-state X-ray absorption spectra, highlighting their relative performance.

Findings

Coupled-cluster methods show high accuracy for uracil and thymine.

Maximum overlap DFT offers a computationally efficient alternative.

Guidelines are provided for choosing suitable methods based on system and accuracy needs.

Abstract

We assess the performance of different protocols for simulating excited-state X-ray absorption spectra. We consider three different protocols based on equation-of-motion coupled-cluster singles and doubles, two of them combined with the maximum overlap method. The three protocols differ in the choice of a reference configuration used to compute target states. Maximum-overlap-method time-dependent density functional theory is also considered. The performance of the different approaches is illustrated using uracil, thymine, and acetylacetone as benchmark systems. The results provide guidance for selecting an electronic structure method for modeling time-resolved X-ray absorption spectroscopy.