The accuracy of the simple linear relation in Figure illustrates that, indeed, the site preference energy in d 0 -metal-and lanthanide-based Mg chalcogenide spinels seems to predominantly depend on the influence of the trigonal distortion on the competition between bond length and coordination and thus is independent of the lattice constants. While the trigonal distortion is mostly related to the metal B and thus the ratio of distances k64, also the anion affects the inherent competition between sites as evident by the contribution of the anionic radius rX in Figure . In addition, the triangular transition state is affected by the increase in trigonal distortion as illustrated in Figure . Here, the trigonal distortion increases the area of the transition state and thus reduces the migration barriers. Nevertheless, the here presented data set does not allow to unambiguously attribute the influence on EKRA solely on the trigonal distortion independent of the lattice constants. While the site preference energy ΔE seems to predominantly dependent on the trigonal distortion and the competition between bond length and coordination, further studies on an increased chemical space that allows to decouple the effects of cell volume and trigonal distortion are required to clarify the chemical trends underlying EKRA.