State-to-state quantum dynamics of the H + LiF → Li + HF reaction on an accurate ab initio potential energy surface

Abstract

Quantum state-to-state dynamics calculations are reported for the H + LiF(vi, ji) → HF(vf, jf) + Li reaction on a recently reported ground state X̃2A′ potential energy surface. It was found that at low collision energies the title reaction is dominated by long-lived resonances, while the lifetimes of resonances become shorter at higher energies. The existence of resonances is also supported by the differential cross section, which has mostly forward and sideways bias. The integral cross section rises with collision energy slowly, and the opacity function suggests that the reaction is dominated by small impact parameter collisions. The HF product has cold vibrational state distributions in range of the collision energy studied here, although its rotational state distributions peak near the highest accessible rotational states. This early-barrier reaction shows some enhancement by translational energy, but internal excitations of the LiF reactant have more complex behaviors.