# Mutual neutralization in Li$^+$-D$^-$ collisions: a combined experimental and theoretical study

## TL;DR

This study combines experimental measurements and theoretical calculations to analyze mutual neutralization in Li+ and D- collisions at low energies, providing validated cross sections and rate coefficients relevant for astrochemistry.

## Contribution

It offers a comprehensive experimental and theoretical analysis of mutual neutralization in Li+ and D- collisions, highlighting the importance of high-precision data for validating models.

## Key findings

- Excellent agreement between experiment and theory across energies.
- Basis set choice affects partial cross sections and reaction branching ratios.
- Computed rate coefficients are relevant for astrochemical models.

## Abstract

We present a combined experimental and theoretical study of the mutual neutralization process in collisions of lithium ions (Li+) with deuterium anions (D-) at collision energies below 1 eV. We employ a merged-beam apparatus to determine total and state-to-state mutual neutralization cross sections. We perform nuclear dynamics calculations using the multi-channel Landau-Zener model based on accurate ab initio molecular data. We obtain an excellent agreement between the experimental and theoretical results over the energy range covered in this work. We show that the basis sets used in the ab initio calculations have a limited influence on the total cross section, but strongly impacts the results obtained for the partial cross sections or the reaction branching ratios. This demonstrates the important role of high-precision measurements to validate the theoretical approaches used to study gas-phase reactive processes. Finally, we compute mutual neutralization rate coefficients for Li+ + H- and Li+ + D-, and discuss their significance for astrochemistry models.