Studies of mutual neutralization in collisions involving Mg+/H-, Na+/H-, Li+/H- and Li+/Cl

Sifiso M Nkambule; Oscar N Mabuza

doi:10.1016/j.heliyon.2022.e11443

Studies of mutual neutralization in collisions involving Mg⁺/H^-, Na⁺/H^-, Li⁺/H^- and Li⁺/Cl

Heliyon. 2022 Nov 4;8(11):e11443. doi: 10.1016/j.heliyon.2022.e11443. eCollection 2022 Nov.

Authors

Sifiso M Nkambule¹, Oscar N Mabuza^{1

2}

Affiliations

¹ Department of Physics, Faculty of Science and Engineering, University of Eswatini, Private bag 4 Kwaluseni, M201, Swaziland.
² Department of Physics, Faculty of Science Education, William Pitcher College, P.O. Box 87 Manzini, M200, Swaziland.

Abstract

The Landau-Zener model is used to systematically compute mutual neutralization cross sections for collisions between $M g^{+}$ / $H^{-}$ , $N a^{+}$ / $H^{-}$ , $L i^{+}$ / $H^{-}$ and $L i^{+}$ / $C l^{-}$ . Potential energy curves for electronic states that are relevant for mutual neutralization are taken from available literature. Where non-adiabatic couplings are available, they are utilized to compute the diabatic potential energy curves, crossing distance and electronic couplings. In cases where non-adiabatic couplings are not available, they are approximated using a Lorentzian function. The reaction cross sections are computed for the energy range 0.001 eV to 1000 eV. The results are compared with other available experimental and theoretical results and are found to be very comparable. There is an observable trend in the reaction cross section involving ions of metals and hydrogen at collision energies below 10 eV, with the heaviest metal showing the largest reaction cross section and the lightest metal with the lowest cross section. At collision energies below 10 eV, isotope effect is also found to have an effect on the reaction cross section for $L i^{+}$ / $C l^{-}$ .

Keywords: Avoided crossing; Crossing distance; Landau-Zener model; Mutual neutralization; Non-adiabatic couplings; Reaction cross section.