Quasiclassical trajectory studies of the chlorine-hydrogen system. I. Cl+H₂→HCl+H

Detailed three-dimensional quasiclassical trajectory calculations were performed for the reaction Cl+H₂(0,J)→HCl+H on a semiempirical LEPS potential energy surface. Calculations were carried out for initial vibrational state v=0, rotational states J=0-4, and collision energies E between threshold and 12.0 kcal/mole. From the trajectory calculations we obtained reaction probabilities P_r(v=0, J, E, b) as a function of impact parameter b and initial values of J and E; reaction cross sections S _r(v=0, J, E) as a function of initial J and E; detailed rate constants k_0,J and total rate constants k_r in the temperature range 250-600°K, and the partitioning of energy and angular distribution of the products for different initial conditions. Thermal rate constants were compared with results of other trajectory studies of this system, with results of transition state theory calculations, and with experimental results. The trajectory rate constants of the present study were found to be in good agreement with experimental results. The results for energy partitioning show that under thermal equilibrium of reactants the products are formed with nearly thermal vibrational and rotational energies. The angular distribution of the products is mainly in the backward direction.