THEORETICAL CHARGE-TRANSFER CROSS-SECTIONS FOR H-]H(S-2(G))+HCL+(A (2)SIGMA(+)) FROM A DIATOMICS-IN-MOLECULES EFFECTIVE HAMILTONIAN(+HCL(X (1)SIGMA(+)))

A projection matrix technique is used to construct a two-state effecti ve Hamiltonian matrix from a diatomics-in-molecules model (10 x 10 mat rix) for the H2Cl+ molecule. This is applied to the computation of the dependence on collision energy of the cross-section for the charge-tr ansfer process H+ + HCl(X (1) Sigma(+)) --> H(S-2(g)) + HCl+(A (2) Sig ma(+)). The reaction probabilities are estimated by the Landau-Zener a pproximation within the context of simple straight-line trajectories. The results, which in general overestimate the experimentally measured cross-sections, are discussed in terms of the properties at the cross ing of the diabatic states and are compared with earlier calculations.