Ammonium zinc vanadium phosphate, (NH4)3Zn2V(PO4)2(HPO4)2

The title compound, triammonium dizinc vanadium bis(phosphate) bis(hydrogen phosphate), (NH4)(3)Zn2V(PO4)(2)(HPO4)(2), is the first ammonium zinc vanadium phosphate. It is built up from a three-dimensional network of vertex-sharing VO6 octahedra and ZnO4, PO4 and HPO4 tetrahedra fused together via V-O-P and Zn-O-P bonds [d(av)(V-O) = 2.001 (2), d(av)(Zn-O) = 1.949(2) and d(av)(P-O) = 1.538(2)Angstrom; theta(av)(V-O-P) = 142.5 and theta(av)(Zn-O-P) = 131.6 degrees]. NH4+ cations occupy two different types of interstices in the Zn-V-P-O framework.