Differential photoionization cross section calculations for HI using the random-phase approximation with L2 basis functions

✍ Scribed by I. Cacelli; R. Moccia

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 837 KB
• Volume: 60
• Category: Article
• ISSN: 0020-7608
• DOI: 10.1002/(sici)1097-461x(1996)60:1<409::aid-qua40>3.0.co;2-4

✦ Synopsis

The photoionization cross sections and asymmetry parameters of the three main valence ionization processes in HI, corresponding to the formation of, respectively, 6a, l l u , and 10 (T holes, were calculated in the random-phase approximation (RPA). Our particular computational procedure, based on solving the integral equation for the half on the shell K-matrix upon a grid of points supplied by an L2 basis set calculation, affords recovery of the electronic continuum degeneracy of the final states. This makes it possible to compute the differential ionization cross section at any energy up to the fourth ionization threshold, allowing for the interaction of the three channels considered. The total cross section obtained by applying the Stieltjes imaging procedure to the discrete spectrum yielded by the RPA is also reported. 0 1996 John Wiley & Sons, Inc. the projection of both bound and continuum molecular electronic states on basis sets of square integrable (L2) functions [ 11 have some definitive advantage on the traditional "scattering" techniques, essentially because they allow one to take into account the multicenter nature of the problem and to easily implement different levels of approximation. Thus, these L2 methods, which are largely