Relative ordering of 4Se, 4De, and 4Do doubly excited states of lithium isoelectronic sequence

Abstract

Orbital configuration classification for the lower 4Se and 4De doubly excited states of lithium isoelectronic sequence is proposed as a function of the nuclear charge on the basis of Hartree-Fock energies of 1s 2sns4Se, 1s 2pnp4Se, 1s 2snd4De, 1s 2pnp4De, and 1s 2pnd4Do states. It is found that the asymptotic relative order of states predicted by nuclear charge expansion method is attained by Z as low as 6. Hartree-Fock energies of 4De and 4Do states are used in conjunction with Holoien and Geltman's 4Po and 4Pe energies to compare assignment of lines obtained in the beamfoil spectra of BeII, CIV, and NV.