THEORETICAL CHARGE-TRANSFER CROSS-SECTIONS FOR H-]H(S-2(G))+HCL+(A(2)SIGMA(+)) .2. CLASSICAL PATH TRAJECTORY CALCULATIONS(+HCL(CHI(1)SIGMA(+)))

Using a classical path surface hopping trajectory calculation, we esti mate the dependence on collision energy of the cross section for the c harge-transfer process H+ + HCl(X(1) Sigma(+)) --> H(S-2(g)) + HCl+(A( 2) Sigma(+))(upsilon'). The motion of the nuclei is treated classicall y and the evolution of the electronic wave function is obtained from t he time-dependent Schrodinger equation, using a (10 x 10) Hamiltonian matrix from a diatomics-in-molecules model for the (1)A' 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 state s show qualitative agreement with experiment but depend very strongly on some of the details of the method, in particular on the way in whic h the distribution of the initial internuclear distance of the molecul e is chosen: correct results require a quantum mechanical distribution . Cross sections for dissociation and for the production of ground sta te product molecules HCl+(X(2) Pi) are also obtained, the latter being the major channel at all collision energies studied in the range 5 < E < 2000 eV. The non-adiabatic nature of the collisions is shown to in volve at least four electronic states. Comparison with earlier Landau- Zener calculations is discussed.