Excitation energies of 1s2nd and 1s2nf states for the lithium isoelectronic sequence

Abstract

The nonrelativistic energies of the 1s(2)nd and 1s(2)nf(n=6, 7, 8 and 9) states for the lithium isoelectronic sequence from Li I to Ne VIII are calculated by using a full core plus correlation method with multiconfiguration interaction wave function. Relativistic and mass-polarization effects on the energy are evaluated as the first-order perturbation theory. In most cases with nuclear charge, Z less than or equal to 7, the agreement between our predicted excitation energies and the experimental data is less than 1 cm(-1).