Accurate quantum mechanical rate coefficients for D + H2(v, j) reaction: From ultracold to thermal temperature limit

Abstract

Reactive scattering dynamics at ultra-low collision energies have been investigated for field free D+H2(v,j) reaction using time-independent quantum close coupling approach. Accurate rate coefficients for reactive collisions have been calculated from ultracold (∼1mK) to thermal (∼500K) temperature range. Quantum mechanical rate coefficients start to diverge from usual Arrhenius behavior at T∼150K and become constant as the temperature is lowered to ultracold temperature limit. This non-Arrhenius behavior at low temperatures is general for barrier dominated reactions and attributed to quantum mechanical tunnelling.