Oscillator Strengths in the Aluminum Sequence

The structures of the 3 s 2 3 p 2 P 0 ground state and of a number of excited states for aluminum and ions along the isoelectronic sequence up to Ca VIII have been calculated in the Multiconfiguration Optimized Potential Model. The excited states include the following: 3 s 2 3 d 2 D , 3 s 2 4 s 2 S , 3 s 3 p 2 2 D , 2 S , as well as 3 s 2 4 p , 3 p 3 and 3 s 3 p ( 3 P 0 )3 d 2 P 0 . There is strong configuration mixing in the spectroscopic terms but on the basis of our calculations we recommend a different designation from that currently adopted for the 3 p 3 and 3 s 3 p ( 3 P 0 )3 d 2 P 0 terms. Oscillator strengths for transitions among these terms have been calculated in the length and velocity formulation with particular emphasis on accurate description in the vicinity of term crossings. Comparison is made with other theory and with experiment where results are available. At present, the experimental data are inadequate to verify the many calculated structures in the isoelectronic gf dependence.