Relativistic excitation energies and oscillator strengths including core-polarization effects for the intercombination and resonance transitions in Mg-like ions

Abstract

Excitation energies and oscillator strengths from the 1S0 ground state to the first 3P10 and 1P10 excited states of Mg-like ions are calculated using the multiconfiguration relativistic random-phase approximation including excitation channels from core electrons. The discrepancies between the relativistic random-phase approximation calculation and experimental results for the intercombination excitation energies and oscillator strengths are much reduced. The excitation energies and oscillator strengths for the resonance transition from the multiconfiguration relativistic random-phase approximation are in excellent agreement with experiment. A substantial part of the discrepancy in the 3P10-1P10 separations is resolved when core excitation channels are taken into account.