Electronic structure of FeCr2S4: Evidence of Coulomb enhanced spin-orbit splitting

The electronic structure of the spinel compound, FeCr2S4, is studied using density-functional-theory-based calculations. Our calculations provide a microscopic understanding of the origin of the insulating behavior of this compound, which turn out to be driven by Coulomb enhanced spin-orbit coupling operative within the Fe-d manifold. We also investigate the possible role of the structural distortions and compare the calculated optical property data with that of the experimental one.