CONVERGENT MULTICHANNEL CONTINUUM STATES BY A GENERAL CONFIGURATION-INTERACTION EXPANSION IN A B-SPLINE BASIS - APPLICATION TO H- PHOTODETACHMENT

We report the theoretical calculation of the total and partial cross s ection and asymmetry parameter for H- photoionization up to the N = 3 threshold. Multichannel continuum wavefunctions are obtained via a lea st squares solution of the Schrodinger equation employing a basis set expansion based on a primitive B-spline radial basis and a general con figuration interaction (CI) form. This allows the use of a mixed full- CI and close coupling expansion in a completely general approach to im prove correlation description in the continuum channels. The present a lgorithm correctly describes the full range of phenomena encountered w ith remarkable accuracy both on nonresonant cross sections and resonan ce structures. An accuracy of better than 0.01 Mb is estimated on both the total and partial cross sections, except for the shape resonance. In addition, Fano resonance parameters compare very well with the bes t methods available based on Hylleraas-type wavefunctions and complex coordinate rotation.