Energy levels and radiative rates for transitions in Fe V, Co VI and Ni VII

Abstract

a b s t r a c tEnergy levels, Landé g-factors and radiative lifetimes are reported for the lowest 182 levels of the 3d 4 , 3d 3 4s and 3d 3 4p configurations of Fe V, Co VI and Ni VII. Additionally, radiative rates (A-values) have been calculated for the E1, E2 and M1 transitions among these levels. The calculations have been performed in a quasi-relativistic approach (QR) with a very large configuration interaction (CI) wavefunction expansion, which has been found to be necessary for these ions. Our calculated energies for all ions are in excellent agreement with the available measurements, for most levels. Discrepancies among various calculations for the radiative rates of E1 transitions in Fe V are up to a factor of two for stronger transitions (f ≥ 0.1), and larger (over an order of magnitude) for weaker ones. The reasons for these discrepancies have been discussed and mainly are due to the differing amount of CI and methodologies adopted. However, there are no appreciable discrepancies in similar data for M1 and E2 transitions, or the g-factors for the levels of Fe V, the only ion for which comparisons are feasible.

Constraining the magnetic field on white dwarf surfaces; Zeeman effects and fine structure constant variation

“…inAggarwal et al (2017).Using the above procedure to define the parameter set for each Zeeman component, vpfit 4(Carswell & Webb 2014) is run multiple times, externally varying the magnetic field B. Each Zeeman component is taken to be a Voigt profile for convenience.…”