Nonadiabatic phase-matrix method for vibrational excitation and dissociative attachment in electron-molecule scattering

The R-matrix theory of vibronic processes in electron-molecule scattering is developed from a generalized variational formalism, valid for any enclosed system of interacting particles with different mass parameters. The question of choice of variational basis functions is discussed, examining practical reasons for using basis functions that do not have specified boundary values or normal gradients on the boundary surface of the enclosed volume. A nonadiabatic theory is derived in which the vibronic R matrix, including channels describing dissociation processes, is deduced from the fixed-nuclei electronic R matrix, given as a function of electronic energy and internuclear distance. © 1996 The American Physical Society.