Nonrelativistic energies for the lowest 4P° states of the Li isoelectronic series

Upper bond calculations for the lowest 4P° states of the Li isoelectronic series from LiI-Ne VIII are given. Using large double lined Hylleraas-CI calculations high accuracy was achieved. We obtained in the infinite-mass approximation the energy of the lowest 4P° state of the Li E = −5.36801014 Eh. Furthermore, a comparison is given with experimental data especially concerning the transition of 2 4P° → 3 4S.