Abstract
We report on the bonding in skutterudites using the CoSb3 example. The theoretical electronic structure is calculated in both density-functional theory and empirical tight-binding frameworks. It is shown to be in good agreement with x-ray photoemission and photoabsorption experiments, and with Sb Mössbauer spectroscopy. It is then used to demonstrate that (i) the Sb4 rings are not the main structural features to analyze the highest valence-band behavior, (ii) the structure must be described in terms of comer-connected CoSb6 octahedra, which are tilted to form the Sb rings.