Relativistic quantum defect orbital study of forbidden transitions in Co

Theoretical line strengths and transition probabilities for electric quadrupole (E2) transitions between levels belonging to several important configurations of Co16+ are reported. The calculations have been carried out with the Relativistic Quantum Defect Orbital (RQDO) method. A general good accord between the present results and some earlier theoretical data is found. Some of the E2 transition probabilities are reported for the first time. The correct systematic behaviour of the RQDO line strengths along the spectral series is reproduced by the present results in the absence of configuration mixing. This semiempirical method appears to adequately describe E2 transitions in this medium-Z atomic system