APPROXIMATE DIATOMICS-IN-MOLECULES POTENTIAL-ENERGY SURFACES AND NON-ADIABATIC COUPLING FOR HE++H2

The method of diatomics-in-molecules (DIM) which constructs the hamiltonian matrix semi-empirically from known atomic and diatomic fragment energy data, is used to generate approximate 3D potential energy hypersurfaces and non-adiabatic coupling coefficients for the system (HeHH)+. To reduce the size of the matrices, a heuristic truncation of the basis set is proposed. The resulting potentials for the two lower excited electronic states are discussed with respect to inelastic scattering and dissociative charge-transfer in collisions He+ + H2. © 1979.