Theoretical study of the valence and core photoionization of a three-electron system from lithium to neon

The multiconfiguration Hartree-Fock (MCHF) method for continuum wavefunctions is used to study the photoionization of lithium and ions of its isoelectronic sequence for photon energies from 0.1 to 250 Ryd. Electron correlation and polarization effects in the initial and final states and relaxation and correlation in the final ionic states, which are found to be very important in the valence- and K-shell partial photoionization cross sections, have been taken into account accurately in an ab initio manner through the configuration interaction procedure. The present results are compared with available experimental measurements and accurate theoretical data for a limited energy range and are found to be in good agreement