Vibrational population inversion in hydrogen iodide from H+I2→ HI+I

A classical trajectory analysis for the reaction ${\mathrm{H+I}}_2\to \mathrm{HI+I}$ at 600°K, using trajectories sampled within the transition region, shows vibrational excitation of the HI product molecules, mainly to the v=3 to v=5 levels. The calculated thermal rate is in approximate agreement with measurements by Sullivan. The product angular distribution is peaked at 110–120° relative to the incident atoms as measured for the reaction of D atoms by McDonald, LeBreton, and Herschbach. The translational energy distribution of the products is also similar to that found by McDonald et al. for the deuterium analog.