Open framework crystalline solids have great potential as catalysts and absorbers and for many other applications in materials science. The synthesis and structural characterization of a new zinc phosphate prepared from a predominantly non-aqueous system are described. The unique features of the compound, which has the empirical formula Zn4(PO4)3(H2O)(C2H5NH3), such as three-coordinated oxygen atoms and a ratio of Zn to P greater than 1, are discussed.