Figure -f illustrates the dependence of ΔE on the ratio of the bond distances k64 between the central cation and the Se anions in the octahedron (d(cn6)) and tetrahedron (d(cn4)) that was proposed to determine the site preference energy. In terms of site preference energy linearity, k64 outperforms significantly when compared to the ionic radii (rB), as evidenced by its superior R 2 and mean squared error. To the best of our knowledge such a relation of the ionic radius and the anion dilation parameter u was so far not derived for sulfide and selenide spinels, so that we resort to calculated bond lengths d(cn6) and d(cn4) based on DFT calculations.