Analysis of the resonant states of H-associated with the n=2 and n=3 thresholds of atomic hydrogen

The reduced IERM approach is applied to electron scattering from hydrogen atoms below the n=2 and n=3 thresholds to obtain accurate widths and positions for the resonant states of H - in this energy region, together with integrated cross sections for n=1 to n=2 transitions. Comparison with standard R-matrix results, where only bound states have been included in the close coupling expansion, indicates the importance of including the continuum channels even at these low energies. The results are in good agreement with coupled pseudostate and recent J-matrix calculations.