New theoretical developments in electron-atom and electron-molecule processes

The 1977-1979 developments of ab initio methods simultaneously aiming at the qualitative understanding and quantitative prediction of a wide variety of atomic and molecular processes are given. The authors describe four new developments. The variable phase method appears as a flexible tool to solve the long range coupled scattering equations producing the K-matrix by direct outward integration and if necessary the scattering solutions in compact form (variable phase amplitude method). The momentum transfer theory of angular distribution applied to scattering and photoionization processes, allows a finer analysis of the predictions and more complete comparisons with experiment. The variable phase method, combined with the frame transformation idea, provides a simplified description of scattering problems involving a large number of nearly degenerate dissociation channels such as the direct rotational (vibrational) excitation of molecules near threshold. (Auth.)