H+LiH⁺ collision dynamics at ultracold temperature conditions

Abstract

Dynamics of H + LiH⁺ (v = 0, j) collisions is investigated at cold and ultracold temperature conditions by a time-independent quantum mechanical method. The ab initio potential energy surface of the electronic ground state of the collisional system developed by Martinazzo et al. (2003) is used in the dynamics study. The collision dynamics at energy as low as 10^-9 eV has been examined. The Wigner threshold law holds in the limit of vanishing collision energy. Extremely large rotational and vibrational excitation of the product H₂, formed via the LiH⁺ depletion channel, is found from the theoretical results. Integral cross sections and temperature dependent rate constants are reported for the H₂ formation path. While elastic collision remains the dominant process, the depletion and inelastic processes also contribute to the dynamics with rotational excitation of the reagent LiH⁺ at ultracold temperature conditions and for s-wave scattering.