Structure and properties of ilmenite from first principles

Abstract

The electron structure, magnetic, structural, and elastic properties of ilmenite $(\mathrm{Fe}\mathrm{Ti}{\mathrm{O}}_{3})$ are computed within a hybrid density functional formalism. The computed properties are found to be very sensitive to the treatment of electronic exchange and correlation; Hartree-Fock and generalized gradient approximation calculations are performed for comparison. Within the hybrid formalism a qualitatively correct description of the ground-state electronic structure is obtained. Predicted geometric and elastic parameters are in close agreement with experiment as is the charge transfer excitation energy. The essential features of this functional are its treatment of the electronic self interaction and its reasonable estimate of the pair correlation energy of the doubly occupied $\mathrm{Fe}\text{\ensuremath{-}}d$ orbital.