Dynamics of some hydrogen isotopic exchange reactions at high energies

Classical trajectory studies have been performed using an empirical potential energy surface for the interactions H + H2, D + D2, T + H2, T + D2, H + T2 and T + HD. Reaction and dissociation cross sections in each system are examined and a simple rule of thumb for estimating the low energy reaction efficiency is described. The integrated reaction cross section ratios for the tritium atom reactions are found to be in good agreement with observed experimental isotope effects. The vibrational excitation of the product molecule and the centre of mass scattering distributions are also discussed.