Photoionization of closed-shell atoms: Hartree-Fock calculations of orientation and alignment

A complete theoretical study of the orientation and alignment parameters A(10) and A(20) is provided for the single photoionization of atoms with the ground state S-1(0). That is, the elements Ne, Mg, Ar, Ca, Zn, Kr, Sr, Pd, Cd, Xe, Ba, Yb, Hg, Rn, Ra and No and all possible vacancies from 2p(1/2) UP to 6p(3/2) have been investigated. The numerical calculations have been done by applying a relaxed orbital method within a single-configurational Hartree-Fock approach where mass-velocity and Darwin contributions have been accounted for. Kinetic energies of the emitted photoelectron up to at least 20 Rydbergs (approximate to272 eV) have been considered. The accuracy of the numerical results is assessed from a comparison with experimental data. (C) 2003 Elsevier B.V. All rights reserved.