Isoelectronic smoothing of line strengths in intermediate coupling

Abstract

where J and 7 are the total angular momentum and lifetime of the upper level, and A is the transition wavelength. Ref-A method is presented that accounts for the effects of singlet-triplet mixing in measured lifetimes of resonance and intercombination lines in alkaline-erenceS [1-31 have demonstrated that Of for Some earthlike and inert-gaslike isoelectronic sequences, The method uses measured isoelectronic sequences can be accurately represented by a lifetimes and spectroscopic energy levels as its only inputs, and yields mixing-semiempirical screening parameter linearization of the form reduced line strength factors that can be isoelectronically linearized for precision interpolation, extrapolation, and smoothing. The method is 22s = A + B/(Zc).applied to predictively systematize lifetimes in the Be, Mg and Ne isoelectronic sequences.

Dipole allowed and intercombination transitions in K$^{\mathsf7+}$ and Ti$^{\mathsf{10+}}$ ions

“…Comparisons are made with other available calculations and the measurements of Curtis (1991) and Biémont et al (2002). We note that our results give excellent agreement with the measurements.…”

“…In order to assess the accuracy of theoretical methods for transition rates, it is essential to have reliable experimental values for comparison. A number of comparatively accurate experimental values are available (Curtis 1991) both for the allowed transition 3s 2 ( 1 S 0 )-3s3p( 1 P 1 ) and for the intercombination transition 3s 2 ( 1 S 0 )-3s3p( 3 P 1 ).…”

Determination of lifetimes and nonadiabatic correlations from measured dipole polarizabilities

“…Similar predictive semiempirical parametrizations of measured data have been carried out for the Mg [24], Cd [26] and Hg [27] sequences. These studies could be greatly improved by the addition of lifetime values deduced from precision spectroscopic determinations of α d using the methods described here.…”

“…It can be deduced from the oscillator strength using [22] g 4s f 4s,4p = 2 3 E 4s,4p S 4s,4p (18) (energy in au), where f 4s,4p is determined either from the measured value of τ 4p using equation (12), or from the measured value of α d using equation (4). There is much empirical evidence [23][24][25][26][27] indicating that ions with one or two out-ofshell electrons exhibit a nearly linear isoelectronic variation when the line strength factor is scaled quadratically with the nuclear charge Z and plotted against a suitably chosen reciprocal screened charge. Thus…”

“…The solid diamond represents the hydrogenic value S H = 1080. In the case of two-valence-electron systems, it is also possible to take into account the effects of intermediate coupling [24] using the singlet-triplet mixing angle obtained from equation (8). First, line strength factors S(Res) and S(Int) are deduced from measured lifetimes for the resonance and intercombination transitions.…”