Electronic structure and lattice relaxation related to Fe in MgO.

The electronic structure of Fe impurity in MgO was calculated by the linear muffin-tin orbital–full-potential method within the conventional local-density approximation (LDA) and making use of the LDA+U formalism. The importance of introducing different potentials, depending on the screened Coulomb integral U , is emphasized for obtaining a physically reasonable ground state of the Fe ion configuration. The symmetry lowering of the ion electrostatic field leads to the observed Jahn–Teller effect; related ligand relaxation confined to tetragonal symmetry has been optimized based on the full-potential total energy results. The electronic structure of the Fe ion is also calculated and compared with that of Fe. 31.20.-d, 71.10.+x, 71.25.Tn Typeset using REVTEX