Effects of Breit interaction on theL2,3x-ray absorption near-edge structures of 3dtransition metals

Abstract

${L}_{2,3}$ x-ray absorption near-edge structures (XANES) of $3d$ transition metal (TM) ions and their compounds are calculated by the all-electron relativistic configuration interaction method. The Breit interaction term, which is the first relativistic correction term for the electron-electron interaction in the quantum electrodynamics, is taken into account in the many-electron Hamiltonian. Then the effects on the multiplet structure for $3d$ TM ${L}_{2,3}$ XANES are investigated. The energy separation between ${L}_{3}$ and ${L}_{2}$ edges of theoretical spectrum decreases when the Breit interaction term is taken into account. At the final states of ${L}_{2,3}$ XANES, the Breit interaction energies linearly depend on the occupation number of TM $2{p}_{3∕2}$ orbitals. They are not influenced by the valency and the crystal field. This main contribution of the Breit interaction term is, therefore, calculated to be the reduction of the separation between ${L}_{3}$ and ${L}_{2}$ edges, which ranges from $0.49\phantom{\rule{0.3em}{0ex}}\text{to}\phantom{\rule{0.3em}{0ex}}1.52\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ for Sc to Cu.