Electronic structure of the antiferromagnetic $B1$-structured FeO

Density functional theory (DFT) famously fails to correctly describe the electronic band structure of Mott insulators, such as FeO. Here, we present calculations on the structural, elastic, and electronic properties of antiferromagnetic, NaCl-structured (B1) FeO, employing hybrid functionals that combine fractions of the Becke and Fock exchange in combination with the Lee-Yang-Parr correlation functional. We find that in detail different properties of FeO require the inclusion of different amounts of Fock exchange in order for the simulation to reproduce the experimental values, correctly, e.g., geometry, band gap, and elastic constant; but in general between 30%–60% Fock-exchange gives a good description of lattice parameters, bulk modulus as well as the electronic structure, and this approach is therefore an alternative to the $\mathrm{LDA}+\mathrm{U}$ method that has traditionally been used in the past.

Figure 1

Total denisity of states (DOS) and partial density of states (PDOS) for the (a) BLYP, (b) B3LYP, (c) UHF, and (d) ${\mathrm{H}}_{35}{\mathrm{B}}_{65}\mathrm{L}\mathrm{Y}\mathrm{P}$ Hamiltonians. Energies are given in Hartree.

Figure 2

Band structure for the (a) BLYP, (b) B3LYP, (c) UHF, and (d) ${\mathrm{H}}_{35}{\mathrm{B}}_{65}\mathrm{L}\mathrm{Y}\mathrm{P}$ Hamiltonians. Energies are given in Hartree.