Transition rates of the resonance line doublet in the Cl I sequence, Ar II-Ge XVI

The transition rates involving the lowest excited level in the Cl I isoelectronic sequence, 3s3p 6 2 S 1/2 , have been reinvestigated. Most of the earlier systematic calculations along the isoelectronic sequence are in clear disagreement with the experimental data that are available for elements Ar, Ti, Fe, Ni and Cu so far. New, extensive and systematic calculations give hints at why the earlier calculations fell short of their goal. The new results are the first that yield a consistent isoelectronic trend that is compatible with the trend of the experimental data.