Quasiclassical trajectory studies of the H+H2 reaction on an accurate potential-energy surface. III. Comparison of rate constants and cross sections with experiment

Abstract

Quasiclassical trajectories computed for the H+H₂ reaction on the accurate Siegbahn–Liu–Truhlar–Horowitz potential‐energy surface are presented. Reaction rate constants as a function of temperature for H₂ in the ground and first excited vibrational state are compared with experimental rate data. For v = 0, agreement is found to be excellent for all isotopic combinations. For v = 1, however, all theoretical results predict much smaller rate constants than are observed experimentally. This discrepancy cannot be ascribed to the absence of tunneling inherent in classical mechanics and is unlikely to be due to errors in the surface. Angular distributions in the laboratory frame have been computed from theoretical results for D+H₂ and H+T₂ and compared with recent experiments. Agreement is fairly good.