Reactive scattering calculations on a splinefitted ab initio surface: the He+H⁺₂(v=0,1,2) →HeH⁺+H reaction

Abstract

The reaction probabilities for He+H⁺₂(v=0,1,2,3)→HeH⁺+H have been computed as a function of total energy using quasiclassical trajectory procedures. The potential-energy surface was obtained by employing 2D cubic spline interpolation of previously reported ab initio SCF results. The calculated reaction probabilities are found to be significantly increased whenever the total energy is selectively partitioned into H⁺₂ vibration. These results are in accord with previously reported experimental findings but are in contrast to previous quantum mechanical calculations on a DIM analytic fit to the ab initio surface points. It is shown that this discrepancy is a result of small differences between the splinefitted and DIM surfaces and not to either the collinear nature of the computations or the differences between quantum and quasiclassical procedures.