Electronic and magnetic structure ofMnF2andNiF2

Abstract

We present an ab initio study of the electronic and magnetic structure of the antiferromagnetic state of ${\mathrm{MnF}}_2$ and ${\mathrm{NiF}}_2$. From the band structures of these two compounds we derive densities of states (DOS), electron densities, spin densities, electric-field gradients, and total energies. We use a simple molecular-orbital scheme to interpret the results. The internal coordinate u is determined by total-energy minimization for ${\mathrm{MnF}}_2$ and agrees well with experiment as well as with the calculated electric-field gradients or the electron densities. Recent spin-dependent x-ray-absorption spectra are interpreted in terms of partial DOS of the unoccupied Mn 4p states.