2p^4, 4f, 5f, and 5g configurations of quadruply ionized aluminum (Al v)

The analysis of Al v has been extended to the 2p4 4f, 5f, and 5g configurations. The classification of 96 newly observed lines, in the ranges 456–705 Å and 1579–1621 Å, has led to the determination of all the 4f levels, except the pair based on the 1S0 parent, as well as ten 5f levels and seven unresolved pairs of 5g levels. The structures of these configurations have been studied by means of parametric calculations. The first ionization energy of Al v is at 1 240684 cm−1, computed from the polarization formula. New measurements of the 2s2 2p4–2s 2p5 transitions in Al vi are reported.