Photoelectron angular distributions from aligned molecules using the R-matrix method

TL;DR

This paper introduces an advanced computational method for calculating photoelectron angular distributions from aligned molecules, validated through comparisons with experimental and existing theoretical data, enhancing understanding of molecular photoionization.

Contribution

The paper extends the UKRmol code to compute ab initio photoionization amplitudes for complex molecules, resolving molecular alignment, emission angle, and energy, with validation against experimental results.

Findings

Accurate photoelectron angular distributions for CO₂.

Multi-channel effects significantly influence results.

Method shows good agreement with experimental data.

Abstract

We present a new extension of the UKRmol electron-molecule scattering code suite, which allows one to compute ab initio photoionization and photorecombination amplitudes for complex molecules, resolved both on the molecular alignment (orientation) and the emission angle and energy of the photoelectron. We illustrate our approach using CO$_2$ as an example, and analyze the importance of multi-channel effects by performing our calculations at different, increasing levels of complexity. We benchmark our method by comparing the results of our calculations with experimental data and with theoretical calculations available in the literature.