Low-energy H+ + H2 reactive collisions: mean-potential statistical model and role of permutation symmetry

Statistical theory based on a mean isotropic potential deduced from a full potential energy surface is applied to the complex-forming, reactive H(+) + H(2) system in the interval of collision energies E(c) = 10(-3) to 0.5 eV. We present expressions for the reaction probabilities that incorporate the full permutation symmetry of the protons and compare our results with other statistical models and full quantum mechanical approaches that take account this symmetry correctly, approximately, or erroneously for the exchange rearrangement mechanism of the reaction.