A hyperspherical close-coupling calculation of photoionization from the He atom, Li+and C4+ions. I. Below the N=2 threshold

Abstract

The authors give a detailed account of the formulation of the recently developed hyperspherical close-coupling (HSCC) method. Using this method, they have made calculations of photoionization cross sections for the He atom and He-like ions, Li⁺ and C⁴⁺ below the N=2 (the inner electron's principal quantum number) threshold. From analysing the photoionization cross section spectra and resonance structures of the two-electron systems with different nuclear charge, the effect of the interplay between the electron-nucleus and electron-electron interactions on doubly excited states is studied.