Double linked Hylleraas–CI for the lowest 4Pe states of the Li isoelectronic series

An accurate upper bound calculation for the lowest 4Pe states of the Li isoelectronic series from Li I–Ne VIII is given using an extensive double linked Hylleraas–CI calculation. We obtained, in infinite mass approximation, E=−5.24540980 Eh for the 2 4Pe state of the Li atom. Additionally we discuss the transitions 2 4Po→2 4Pe and 2 4Pe→3 4S and give a comparison to other calculations and experimental data.