Tris(2-carbamoylguanidinium) hydrogen fluoro­phospho­nate fluoro­phospho­nate monohydrate

The title structure, 3C(2)H(7)N(4)O(+)·HFPO(3) (−)·FPO(3) (2−)·H(2)O, contains three independent 2-carbamoylguanidinium cations, one fluoro­phospho­nate, one hydrogen fluoro­phospho­nate and one water mol­ecule. There are three different layers in the structure that are nearly perpendicular to the c axis. Each layer contains a cation and the layers differ by the respective presence of the water mol­ecule, the hydrogen fluoro­phospho­nate and fluoro­phospho­nate anions. N—H⋯O hydrogen bonds between the guanylurea mol­ecules that inter­connect the mol­ecules within each layer are strong. The layers are inter­connected by strong and weak O—H⋯O hydrogen bonds between the anions and water mol­ecules, respectively. Inter­estingly, the configuration of the layers is quite similar to that observed in 2-carbamoylguanidinium hydrogen fluoro­phospho­nate [Fábry et al. (2012). Acta Cryst. C68, o76–o83]. There is also present a N—H⋯F hydrogen bond in the structure which occurs quite rarely.