Effects of Breit interaction on the $L_{2,3}$ x-ray absorption near-edge structures of 3$d$ transition metals
Hidekazu Ikeno and Isao Tanaka

$L_{2,3}$ 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 (QED), 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 $2p_{3/2}$ 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 to 1.52 eV for Sc to Cu.

© 2008 The American Physical Society.