Application of the non-adiabatic phase matrix method to vibrational excitation near a short-lived resonance: The case of e-H₂ scattering

We have applied the non-adiabatic phase matrix method for vibrational scattering processes to a system which supports an extremely broad (short-lived) shape resonance. This method provides a unified, systematic treatment of the range of physical effects that influence the collision as the nuclear geometry varies, from strongly resonant to purely background scattering. For this implementation we have chosen the prototypical 2Σu shape resonance in e-H2 scattering below 10 eV. We compare vibrational cross sections 0 → 1 and 0 → 2 from the present non-adiabatic theory to results from fully converged body-frame vibrational close-coupling calculations and from purely adiabatic studies using the energy modified approximation.