Efficient electronic structure calculation for molecular ionization dynamics at high x-ray intensity

TL;DR

This paper introduces an efficient computational method for simulating molecular ionization dynamics under high-intensity x-ray pulses, enabling detailed studies of multiphoton ionization and nuclear effects relevant for x-ray imaging.

Contribution

The authors develop a novel electronic-structure approach using numerical atomic orbitals for core-hole states, improving the efficiency of modeling complex ionization processes during XFEL interactions.

Findings

Efficient calculation of multiple-hole configurations in molecules.

Suitable for studying x-ray multiphoton ionization and nuclear dynamics.

Provides essential insights for high-intensity x-ray imaging applications.

Abstract

We present the implementation of an electronic-structure approach dedicated to ionization dynamics of molecules interacting with x-ray free-electron laser (XFEL) pulses. In our scheme, molecular orbitals for molecular core-hole states are represented by linear combination of numerical atomic orbitals that are solutions of corresponding atomic core-hole states. We demonstrate that our scheme efficiently calculates all possible multiple-hole configurations of molecules formed during XFEL pulses. The present method is suitable to investigate x-ray multiphoton multiple ionization dynamics and accompanying nuclear dynamics, providing essential information on the chemical dynamics relevant for high-intensity x-ray imaging.