EXCITATION ENERGIES OF 1s²nd AND 1s²nf STATES FOR THE LITHIUM ISOELECTRONIC SEQUENCE

The nonrelativistic energies of the 1s²nd and 1s²nf(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 pertur bation theory. In most cases with nuclear charge, Z≤7, the agreement between our predicted excitation energies and the experimental data is less than 1cm^-1.