Theoretical charge-transfer cross sections for H+ + HCl(X1Σ+) → H(2Sg) + HCl+(A2Σ+) II: classical path trajectory calculations Original Research Article

Using a classical path surface hopping trajectory calculation, we estimate the dependence on collision energy of the cross classically and the evolution of the electronic wave function is obtained from the time-dependent Schrödinger equation, using a (10 × 10) Hamiltonia matrix from a diatomics-in-molecules model for the 1A′ states of the H2Cl+ molecule. The total cross sections are not sensitive to the way in which the dynamical calculations are carried out and agree fairly well with experimental results from the literature. The cross sections for formation of the product molecule in individual vibrational states show qualitative agreement with experiment but depend very strongly on some of the details of the method, in particular on the way in which the distribution of the initial internuclear distance of the molecule is chosen: correct results require a quantum mechanical distribution. Cross sections for dissociation and for the production of ground state product molecules HCl+(X2П) are also obtained, the latter being the major channel at all collision energies studies in the range 5 < E < 2000 eV. The non-adiabatic nature of the collisions is shown to involve at least four electronic states. Comparison with earlier Landau-Zener calculations is discussed.