Accurate calculation of resonances for a central-field model potential

We obtain accurate resonance energies for the Schr\"{o}dinger equation with a central--field potential by means of a method based on a rational approximation to the logarithmic derivative of the wavefunction. We discuss the rate of convergence of our approach and compare present results with those obtained earlier by other authors. We show that present method is superior to the spherical--box approach applied recently to the same problem. As far as we know present results are more accurate than those available in the literature and may be a suitable benchmark for testing future approaches.