Multi-reference protocol for (auto)ionization spectra: application to molecules

TL;DR

This paper introduces a spherically averaged continuum model for calculating molecular photoelectron and Auger spectra, demonstrating its efficiency and reasonable accuracy across various molecules.

Contribution

The study applies a spherically averaged continuum model to molecular spectra, testing different approximations and validating against experimental data for multiple molecules.

Findings

The model estimates spectral shapes and decay rates with reasonable accuracy.

Different approximations, including the one-center approximation, are thoroughly tested.

The approach facilitates interpretation of experimental spectra.

Abstract

We present the application of the spherically averaged continuum model to the evaluation of molecular photoelectron and resonant Auger electron spectra. In this model, the continuum wave function is obtained in a numerically efficient way by solving the radial Schr\"odinger equation with a spherically averaged molecular potential. Different approximations to the Auger transition matrix element and, in particular, the one-center approximation are thoroughly tested against experimental data for the CH$_4$, O$_2$, NO$_2$, and pyrimidine molecules. In general, this approach appears to estimate the shape of the photoelectron and autoionization spectra as well as the total Auger decay rates with reasonable accuracy, allowing for the interpretation of experimental results.