No evidence for cation ordering. The most common error is prediction of compounds which are ordered versions of known disordered compounds. For example, as we will show in detail below, the existence of MgTi 2 NiO 6 is claimed, which is the same as the known ilmenite structure of the same composition, but the predicted structure has ordered Mg and Ni cations, whereas the known structure has those cations disordered. However, no consideration is given by the authors to the possibility that they may have in fact made the known disordered compound instead of their intended com-pound. We show below that this is in fact the most likely situation. This error type is present in 24/36 compounds.