Multichannel close-coupling method with L2 integrable bases

Abstract

A completely L2 method to evaluate continuum states in multichannel scattering problems such as electron-atom collisions, photoionization, etc., is presented. The continuum wavefunction is built from a basis of discretized uncoupled channels. The coupling between channels is introduced, using formal scattering theory, in a pure algebraic way by simply solving a system of linear equations. The advantage of the present approach is that it can be used irrespective of the interaction strength between the uncoupled states. The accuracy of the method is illustrated with some results for both total and partial cross sections in H- photoionization. Resonance parameters for the 1P0 Feshbach resonances converging to the N=3 and N=4 threshold are also provided.