Application of the R-matrix method to Photoionization of Molecules

TL;DR

This paper extends the R-matrix method to molecular photoionization, enabling accurate theoretical calculations for diatomic and polyatomic molecules, demonstrated through nitrogen and nitric oxide molecules with results aligning well with experiments.

Contribution

The work implements the R-matrix method for molecular photoionization using UK codes, broadening its application beyond atoms to complex molecules with multi-configurational states.

Findings

Calculated cross sections agree with experimental data.

Method successfully applied to diatomic molecules.

Demonstrates potential for studying molecular photoionization.

Abstract

The R-matrix method has been used for theoretical calculation of electron collision with atoms and molecules for long years. The method was also formulated to treat photoionization process, however, its application has been mostly limited to photoionization of atoms. In this work, we implement the R-matrix method to treat molecular photoionization problem based on the UK R-matrix codes. This method can be used for diatomic as well as polyatomic molecules, with multi-configurational description for electronic states of both target neutral molecule and product molecular ion. Test calculations were performed for valence electron photoionization of nitrogen (N2) as well as nitric oxide (NO) molecules. Calculated photoionization cross sections and asymmetry parameters agree reasonably well with the available experimental results, suggesting usefulness of the method for molecular photoionization.