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 Fe2+ 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 Fe3+ ion is also calculated and compared with that of Fe2+.
@article{arxiv.cond-mat/9401028,
title = {Electronic Structure and Lattice Relaxation Related to Fe in Mgo},
author = {M. Korotin and A. Postnikov and T. Neumann and G. Borstel and V. Anisimov and M. Methfessel},
journal= {arXiv preprint arXiv:cond-mat/9401028},
year = {2009}
}