Theoretical investigation of the autoionization process in molecular collision complexes: He-*(2 S-3)+Li(2 S-2)-> He+Li++e(-)

A complete ab initio treatment is applied to the autoionization process in the He*(2s S-3) + Li(2s S-2) collisional complex. Feshbach projection based on orbital occupancy, implemented in a multireference configuration intera ction (MRCI) code, defines the resonance state and provides the entrance ch annel potential curve as well as all pertinent information on the resonance -continuum coupling. The l-dependent coupling elements in local approximati on are obtained by projecting a compact one-electron function, named Pennin g molecular orbital (PMO), onto the wave function of the ejected electron w ith proper energy. The continuum wave function is obtained by coupled chann el calculations in the static-exchange approximation. A converged set of se ven complex coupling matrix elements, used in the nuclear dynamics calculat ion based on a complex Numerov algorithm, fully describes the electron angu lar momentum transfer. The calculated angle-dependent spectra, as well as t he total, angle-, and energy-integrated ionization cross sections agree wel l with available experimental data. (C) 2000 American Institute of Physics. [S0021-9606(00)30828-5].