Relativistic Effect on Multiplet Terms of Rare Earth Ions

抄録

Ab initio Spin-Orbit Configuration Interaction (SOCI) calculations for the trivalent lanthanide group ions are presented for the special purpose to investigate the relativistic SO effects on their multiplet terms. The effective nuclear charges (Z_eff's) for one-body spin-orbit Hamiltonian are calculated by an atomic Dirac-Slater Xα equation and applied to the lanthanide ions. The relativistic effects of core electrons can easily be included in the reduction of Z_eff and the multiplet levels shift up to 200, cm^-1 by the reduction. The multiplet energies obtained by the present method are in good agreement with experimental values.