In Fig. , we show some of the structural motifs seen in PS compounds with P/S ≥ 1 and independent P and S anions. They contrast with the polyanionic motifs shown in Fig. for materials with lower P/S ratios. In some of the materials shown in Fig. (Y 2 PS, Ca 4 P 2 S) the coordination environments of P and S are nearly identical, which may promote disorder in the anion sublattice under certain experimental conditions. This can be a beneficial feature, because control over the order parameter in a semiconductor can be exploited to fine-tune its properties. Other materials shown in Fig. (YPS and Zr 2 P 3 S) have rather different coordination environments for P and S, so less prominent disorder effects are expected. Substantial P-S disorder also seems unlikely in thiophosphates because S and P are in significantly different chemical environments with very different oxidation states and ionic radii.