Ro-vibrational excitation of HCl by electrons

Ab initio calculations have been made in the multipole-extracted adiabatic-nuclei approximation. These employed a new parameter-free model of the correlation-polarization interaction and an exact treatment of exchange. Both effects are extremely important. The results for the cross sections v - v' = 0 - 1 and 0 - 2 are in excellent agreement with measurements in shape, but suggest that a renormalization of the measured cross sections by a factor of 0.6 is required. They are consistent with the model of a single electronic state of HCl- coupled to a continuum severely distorted by the dipole potential, yielding both a broad resonance at 2.5 eV at equilibrium and an attractive bound state of HCl- that merges smoothly with the neutral curve at about 2.6 Bohr