Ab-initio calculations of level energies, oscillator strengths and radiative rates for E1 transitions in beryllium-like iron

Abstract

In the present work, energy levels, oscillator strengths, radiative rates and wavelengths of Be-like iron (Fe22+) from ab-initio calculations using the multiconfiguration Dirac-Hartree-Fock method are presented. These quantities have been calculated for a set of configurations in the general form 1s2 nl n'l', where n = 2, 3 and n' = 2, 3, 4, 5 and l = s, p, d and l' = s, p, d, f, g. In addition, excitations of up to four electrons, including core-electron excitations, have been considered to improve the quality of the wave functions. This study comprises an extensive set of E1 transition rates between states with different J. The present results are compared with the available experimental and theoretical data.