Theoretical charge-transfer cross-sections for H+ + HCl(X1Σ+) → H(2Sg) + HCl+ (A 2Σ+) from a diatomics-in-molecules effective Hamiltonian Original Research Article

A projection matrix technique is used to construct a two-state effective Hamiltonian matrix from a diatomics-in-molecules model (10 × 10 matrix) for the H2Cl+ molecule. This is applied to the computation of the dependence on collision energy of the cross-section for the charge-transfer process H+ + HCl(X1Σ+) → H(2Sg) + HCl+ (A2Σ+). The reaction probabilities are estimated by the Landau-Zener approximation 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 crossing of the diabatic states and are compared with earlier calculations.