Ab initio ligand field approach to determine electronic multiplet properties

R. O. Kuzian; O. Janson; A. Savoyant; Jeroen van den Brink; R. Hayn

doi:10.1103/PhysRevB.104.085154

paper

Ab initio ligand field approach to determine electronic multiplet properties

arXiv:2104.10090 · doi:10.1103/PhysRevB.104.085154

Abstract

A method is developed to calculate the ligand field (LF) parameters and the multiplet spectra of local magnetic centers with open $d$ - and $f$ -shells in solids in a parameter-free way. This method proceeds from density functional theory and employs Wannier projections of nonmagnetic band structures onto local $d$ - or $f$ -orbitals. Energies of multiplets and optical, as well as X-ray spectra are determined by exact numerical diagonalization of a local Hamiltonian describing Coulomb, LF, and spin-orbit interactions. The method is tested for several 3 $d$ - and 5 $f$ -compounds for which the LF parameters and multiplet spectra are experimentally well known. In this way, we obtain good agreement with experiment for La $_{2}$ NiO $_{4}$ , CaCuO $_{2}$ , Li $_{2}$ CuO $_{2}$ , ZnO:Co, and UO $_{2}$ .

18 pages, 8 figures