Computing resonance positions, widths, and cross sections via the Feshbach-Fano R-matrix method:: Application to potential scattering -: art. no. 012708

The general Feshbach-Fano R-matrix procedure proposed recently by Nestmann [J. Phys. B 31, 3929 (1998)] makes it possible to construct resonance metastable states of transient molecular ions and their coupling elements to the background scattering continuum. These quantities are needed for the study of nuclear dynamics in the framework of the nonlocal resonance model. The performance of this approach is carefully studied and its properties analyzed in the field of potential scattering. An improvement of the Nestmann procedure which makes the calculation more stable and robust is proposed.