Comparison of the conventional and pseudopotential Feshbach methods: N5+(3l, 3l') 1Se and 1,3P0 resonances

Abstract

The authors report a comparison between two implementations of the Feshbach approach: the conventional partitioning technique, and the pseudopotential method recently proposed by Martin, Mo, Riera and Yanez (1987). They chose as benchmark the N5+(3l, 3l') 1Se and 1,3P0 resonances, which lie above the n=2 ionisation threshold, and which are of experimental interest. Agreement between two Feshbach procedures, even for the partial widths (presented for the first time), and with the results of other accurate calculations, is very encouraging in view of the versatility and computational speed of the pseudopotential method. Useful information on the resonance wavefunctions is provided in terms of weights and contributions to the partial widths from configurations of a given type making up the closed-channel wavefunction.