Energy and fine structure of 1s²nd and 1s²n f states for the lithium isoelectronic sequence

Abstract

The non-relativistic energies of 1s2nd (n=3,4 and 5) and 1s2nf (n=4 and 5) states for the lithium isoelectronic sequence from Li I to Ne VIII are calculated with a full-core plus correlation method using multiconfiguration interaction wavefunctions. Relativistic and mass-polarization effects on the energy are evaluated perturbatively as the first-order corrections. The fine structure is calculated by using spin-orbit and spin-other-orbit interaction operators. The authors results are in excellent agreement with experimental data in the literature. Possible misidentifications in the observed optical spectra are pointed out. They show that this full-core plus correlation method is useful for excited atomic systems with a 1s2 core.