A new formula for determining differential cross sections in the vibronic semiclassical description of atom–molecule collisions

Abstract

A simple approximation applied to the eikonal expression of the scattering amplitude provides a new formula for the determination of differential cross sections for atom–molecule collisions described within the vibronic semiclassical framework. The derived formula achieves considerable savings in the corresponding numerical work and extends the well-known expansion over Legendre polynomials to nonspherical interactions. Results obtained with the new formula on vibrational excitation and vibronic charge exchange in the H++O2 collision at Ecm=23 eV are found to be in excellent agreement with the calculations of Sizun et al. (J. Phys. Chem. Lett.).