A predictive systematization for ns2-nsn' p line strength data

A semiempirical formulation previously used to parametrize line strength data for ns 2 -nsn p alkaline-earth-like resonance and intercombination transitions is extended to study the 2s 2 -2s3p and 3s 2 -3s4p transitions in the Be and Mg isoelectronic sequences. The approach utilizes measured lifetime and energy level data in a linearizing isoelectronic data mapping based on the empirical characterization of singlet-triplet mixing. Although this extension to extrashell transitions introduces complications from plunging configuration interaction, transition integral cancellations and multiple exit channels, the predictive regularities of this method are shown to persist, and to provide insights into the dynamical behaviour of these systems.