Relativistic density-functional calculations of interconfigurational energies in transition-metal atoms

Abstract

The relativistic local-spin-density approximation and the relativistic generalized gradient approximation (RGGA) are employed to calculate interconfiguration energies including $4s$-$3d$ transition energies, $4s$ ionization energies, and $3d$ ionization energies for the first transition-metal atoms. For $3d$ ionizations, the RGGA, which includes relativistic corrections as well as gradient effects, yields the best results. For $4s$-$3d$ transitions, the relativistic effects also systematically improve the accuracies of the results. However the $4s$ removal energies from the relativistic schemes are slightly too large, whereas the self-interaction-correction local-spin-density approximation, which provides correct long-range effective potentials, gives accurate results.