Hybrid theory ofP-wave electron-Li2+elastic scattering and photoabsorption in two-electron systems

Abstract

In previous papers [Bhatia, Phys. Rev. A 85, 052708 (2012); Bhatia, Phys. Rev. A 86, 032709 (2012)] electron-hydrogen and electron-He${}^{+}$ $P$-wave scattering phase shifts were calculated using the hybrid theory. This method is extended to the singlet and triplet electron-Li${}^{2+}$ $P$-wave scattering in the elastic region, where the correlation functions are of Hylleraas type. The short-range and long-range correlations are included in the Schr\"odinger equation at the same time, by using a combination of a modified method of polarized orbitals and the optical potential formalism. Phase shifts are compared to those obtained by other methods. The present calculation requires very few correlation functions to obtain accurate results which are rigorous lower bounds to the exact phase shifts. The continuum functions obtained in this method are used to calculate photodetachment and photoionization cross sections of two-electron systems H${}^{\ensuremath{-}}$, He, and Li${}^{+}$. Cross sections of the metastable ${}^{1,3}S$ states of He, and Li${}^{+}$ are also calculated. These cross sections are calculated in the elastic region and compared with previous calculations. Using these cross sections, the Maxwellian-averaged radiative-recombination rates at various electron temperatures are also calculated.