Structural features of the oxidonitridophosphates K (PO)N ( = Al, Ga).

Cubic crystals of tripotassium aluminium (or gallium) nitridotriphosphate, K (PO)N ( = Al, Ga), were grown by application of the self-flux method. In their isostructural crystal structures, all metal cations and the N atom occupy special positions with site symmetry 3, while the P and O atoms are situated in general positions. The three-dimensional framework of these oxidonitridophosphates is built up from [ O] octa-hedra linked together (PO)N groups.