Relativistic many-body calculations of transition rates from   core-excited states in sodiumlike ions
  Rates and line strengths are calculated for the 2s22p53l3l' - 2s22p63l'' and 2s2p63l3l' - 2s22p63l'' electric-dipole (E1) transitions in Na-like ions with nuclear charges ranging from Z = 14 to 100. Relativistic many-body perturbation theory (RMBPT), including the Breit interaction, is used to evaluate retarded E1 matrix elements in length and velocity forms. The calculations start from a 1s22s22p6 Dirac-Fock potential. First-order RMBPT is used to obtain intermediate coupling coefficients and second-order RMBPT is used to calculate transition matrix elements. A detailed discussion of the various contributions to dipole matrix elements is given for sodiumlike copper (Z = 29). Transition energies used in the calculation of transition rates are from second-order RMBPT. Trends of transition rates as functions of Z are shown graphically for selected transitions. 
U.I. Safronova, W.R. Johnson, M.S. Safronova, and J.R. Albritton