Associative detachment, dissociative attachment, and vibrational excitation of HCl by low-energy electrons

Abstract

An improved nonlocal resonance model for electron-HCl collisions is constructed. The model takes account of the dependence of the dipole-modified threshold exponent on the internuclear distance. The long-range part of the ${\mathrm{HCl}}^{\ensuremath{-}}$ potential-energy function has been determined from the most accurate ab initio calculations which are available. Only the s-wave component of the electronic continuum wave function is taken into account. Cross sections for vibrational excitation, dissociative attachment, and associative detachment have been calculated. For all three collision processes, the cross sections calculated with this model are in better agreement with experiment than previous calculations. The calculations reproduce very well even fine details of the threshold structures in the vibrational excitation cross sections of HCl.