# Multichannel Coupling in the Electronic Excitation of Pyrimidine Induced by Low-Energy Electron Impact

## TL;DR

This paper studies how low-energy electrons interact with pyrimidine molecules, focusing on scattering and excitation processes.

## Contribution

The study introduces a detailed computational approach using the Schwinger multichannel method to calculate cross sections for electron-pyrimidine interactions.

## Key findings

- Elastic scattering cross sections show good agreement with existing data.
- Discrepancies in inelastic cross sections are attributed to multichannel coupling effects.
- Total cross sections were estimated by combining elastic, inelastic, and ionization contributions.

## Abstract

We present elastic and electronically inelastic cross
sections
for the scattering of low-energy electrons by pyrimidine. The calculations
employed the Schwinger multichannel method for impact energies up
to 50 eV. The cross sections were computed within the minimal orbital
basis for single configuration interactions (MOB-SCI) strategy, considering
from 1 to 295 open channels. Our results are compared with theoretical
and experimental data available in the literature. Although we found
good agreement in the elastic scattering, there are discrepancies
between the inelastic cross sections, which are discussed in light
of the multichannel coupling. We also estimated the total cross section
by summing the elastic, electronically inelastic, and total ionization
cross sections, where the latter was obtained using the binary-encounter-Bethe
model.