Abstract
A two-step direct inversion method is described for the determination of non-adiabatic interactions from the corresponding inelastic atom-atom scattering data. In the first step the S-matrix elements are extracted as a function of the angular momentum from the measured inelastic differential cross-section. The second step recovers the interaction function from the S-matrix. The two steps are tested independently for a two-state model of He+/Ne, using numerically simulated data calculated from an assumed interaction potential. Both steps are found to be of very good accuracy, and the interaction function is reproduced to within a few per cent.