Simple discretization method for autoionization widths. II. Atoms

Abstract
We apply a method to calculate autoionization widths of doubly excited states, recently proposed by Mac̆´as and Riera [Chem. Phys. Lett. 117, 42 (1985); Europhys. Lett. 2, 351 (1986); Phys. Lett. 119A, 28 (1986)] and described in detail in the preceding article (this issue), to the lowest (nonrelativistic) He-like Feshbach resonances of 1,3S, P1, 1,3D symmetry. Comparison with accurate data from the literature is shown to be very good. We also present the contributions to the resonance widths from configurations of a given type, or character, making up the closed-channel wave functions. An important advantage of our approach, which is its simplicity, permits us to set up a number of tests for the approximations involved and regarding the use of different discretizing basis sets.