RELATIVISTIC EXCITATION-ENERGIES AND OSCILLATOR-STRENGTHS INCLUDING CORE-POLARIZATION EFFECTS FOR THE INTERCOMBINATION AND RESONANCE TRANSITIONS IN MG-LIKE IONS

Excitation energies and oscillator strengths from the S-1(0) ground st ate to the first (3)p(1)(o) and (1)p(1)(o) excited states of Mg-like i ons are calculated using the multiconfiguration relativistic random-ph ase approximation including excitation channels from core electrons. T he discrepancies between the relativistic random-phase approximation c alculation and experimental results for the intercombination excitatio n energies and oscillator strengths are much reduced. The excitation e nergies and oscillator strengths for the resonance transition from the multiconfiguration relativistic random-phase approximation are in exc ellent agreement with experiment. A substantial part of the discrepanc y in the (3)p(1)(o) -(1)p(1)(o) separations is resolved when core exci tation channels are taken into account.