Radiative rates for E1, E2, M1, and M2 transitions in the Br-like ions Sr IV, Y V, Zr VI, Nb VII, and Mo VIII

Energies and lifetimes are reported for the lowest 375 levels of five Br-like ions, namely SrIV, YV, ZrVI, NbVII, and MoVIII, mostly belonging to the 4s²4p⁵, 4s²4p⁴4ℓ, 4s4p⁶, 4s²4p⁴5ℓ, 4s²4p³4d², 4s4p⁵4ℓ, and 4s4p⁵5ℓ configurations. Extensive configuration interaction has been included and the general-purpose relativistic atomic structure package (grasp) has been adopted for the calculations. Additionally, radiative rates are listed among these levels for all E1, E2, M1, and M2 transitions. From a comparison with the measurements, the majority of our energy levels are assessed to be accurate to better than 2%, although discrepancies between theory and experiment for a few are up to 6%. An accuracy assessment of the calculated radiative rates (and lifetimes) is more difficult, because no prior results exist for these ions.

Energy levels and radiative rates for transitions in Ti VII

We report calculations of energy levels, radiative rates, oscillator strengths and line strengths for transitions among the lowest 231 levels of Ti VII. The general-purpose relativistic atomic structure package and flexible atomic code are adopted for the calculations. Radiative rates, oscillator strengths and line strengths are provided for all electric dipole (E1), magnetic dipole (M1), electric quadrupole (E2) and magnetic quadrupole (M2) transitions among the 231 levels, although calculations have been performed for a much larger number of levels (159 162). In addition, lifetimes for all 231 levels are listed. Comparisons are made with existing results and the accuracy of the data is assessed. In particular, the most recent calculations reported by Singh et al (2012 Can. J. Phys. 90 833) are found to be unreliable, with discrepancies for energy levels of up to 1 Ryd and for radiative rates of up to five orders of magnitude for several transitions, particularly the weaker ones. Based on several comparisons among a variety of calculations with two independent codes, as well as with the earlier results, our listed energy levels are estimated to be accurate to better than 1% (within 0.1 Ryd), whereas results for radiative rates and other related parameters should be accurate to better than 20%.