The generic case of an inorganic material containing phosphorus, sulfur and at least one metal in any stoichiometry and structure will be referred to as phosphosulfide (PS) in this paper. Judging from the number of compounds present in the Materials Project (MP) database , PSs have received less attention than oxygen-containing multi-anion materials. Nonetheless, they are among the non-oxide multi-anion families with the most entries (Fig. ). The "synthesised" bar refers to materials that have also been synthesised in bulk form according to the ICSD database. The known PS materials can crystallize in a wide variety of structures, in which the overall structural dimensionality (i.e., the dimensionality of the network of chemical bonds in the material) can be 3D, 2D, 1D, or 0D. In this paper, we will always refer to the structural dimensionalityrather than the thicknesswhen labeling PS materials as 3D, 2D, 1D, or 0D. PS compounds generally do not react with moisture or oxygen, except for at the surface. An exception is PSs with high alkali metal content, which are often reported to be hygroscopic. Various PSs are also reported to be stable in electrolyte solutions under a wide range of pH values. Thus, PSs are not intrinsically air-sensitive materials.