High-accuracy calculations of term energies and lifetimes of silicon-like ions with nuclear charges Z = 24–30

Abstract

Term energies of the ground and 26 lowest excited levels arising from the 3s23p2, 3s3p3 and 3s23p3d configurations in silicon-like ions with nuclear charges Z = 24–30 are evaluated to high accuracy in relativistic multireference many-body perturbation theory calculations. Theory deviates from experiment on the order of 0.01% for the majority, and by less than 0.2% for all but 13, of the experimentally identified energy levels. Anomalous theory–experiment deviations along the isoelectronic sequence for six excited levels clearly indicate that they have been misidentified, among them the solar lines at 237.61 Å and 259.963 Å. New identifications for the misidentified levels are given based on theoretical wavelengths and lifetimes. Hitherto unidentified 3s23p3d 3Fo2,3,4 decay lines along the isoelectronic sequence are predicted to well within 0.1 Å accuracy. Calculated lifetimes of the odd-parity 3s23p3d 3Fo3 state in silicon-like ions agree reasonably well with experiment, Co13+ being the exception.