Sensitivity of Exchange-Reaction Probabilities to the Potential-Energy Surface

Classical-mechanical calculations were made to study exchange attending collinear collisions of H+H2 using a potential-energy surface proposed earlier by the authors. It was found that the reaction probability is unity for all energies in a certain bounded range, and zero elsewhere. The lower and upper bounds are dependent upon the position of the saddle point of the potential-energy surface and the relative masses of the atoms. No long-lived collision complexes were encountered. The vibrational energies of the final molecules were also found to depend strongly upon the position of the saddle point.