Relativistic correlation effects on the x-ray spectra of Li-like ions

Abstract

The wavelengths and rates of electric dipole transitions between states with $n=2$ and $n=1$ of doubly excited Li-like ions have been studied for some selected ions in the range $13\ensuremath{\le}Z\ensuremath{\le}54$ using fully relativistic multiconfiguration Dirac-Fock wave functions in the active space approximation with the inclusion of finite nuclear size, Breit interaction, self-energy, and vacuum polarization. A detailed discussion on the effects of intercomplex correlation around $Z=26$ and intracomplex correlation around $Z=37$ leading to irregularities and sharp discontinuities in the x-ray rates noticed for a few transitions has been provided. An unusually large contribution of Breit interaction has been found for intercomplex correlation in certain cases. The present results are compared with other available experimental and theoretical data. The errors associated with the transitions are highlighted for some experimentally available lines taking into account the uncertainties on the fine-structure energy levels and also on the line strengths.