Quantum dynamics of the Cl+H2 reaction at ultracold temperatures #

Abstract

Quantum calculations are reported for the reaction between vibrationally excited H2 molecules and Cl atoms at energies ranging from the ultracold to thermal regimes. It is found that chemical reaction leading to vibrationally excited HCl molecules dominates over non-reactive vibrational quenching. The product HCl molecule is found to be formed predominantly in the v = 1 vibrational level with appreciable rotational excitation. A spin-orbit uncorrected value of 1.86 × 10 − 12 cm3 molecule − 1 s − 1 is predicted for the rate coefficient in the zero-temperature limit, which is about two orders of magnitude larger than the thermal rate coefficient of the Cl+H2 reaction at 300 K. Cross sections for non-reactive vibrational quenching leading to Cl+H2(v=0) and chemical reaction leading to HCl+H channels in Cl+H2(v=1, j=0) collisions as functions of the incident kinetic energy.