# UKRmol+: a suite for modelling of electronic processes in molecules interacting with electrons, positrons and photons using the R-matrix method

## TL;DR

UKRmol+ is an advanced computational suite that models electronic interactions in molecules with electrons, positrons, and photons using the R-matrix method, integrating quantum chemistry tools for improved accuracy.

## Contribution

It introduces a new implementation of the UK R-matrix code with enhanced features like quantum chemistry integration and flexible basis functions, expanding capabilities for molecular collision and ionization studies.

## Key findings

- Successfully models electron and positron collisions with molecules.
- Demonstrates improved accuracy with mixed basis functions.
- Provides open-source tools for the scientific community.

## Abstract

UKRmol+ is a new implementation of the UK R-matrix electron-molecule scattering code. Key features of the implementation are the use of quantum chemistry codes such as Molpro to provide target molecular orbitals; the optional use of mixed Gaussian -- B-spline basis functions to represent the continuum and improved configuration and Hamiltonian generation. The code is described, and examples covering electron collisions from a range of targets, positron collisions and photionisation are presented. The codes are freely available as a tarball from Zenodo.