Hexa­aqua­nickel(II) di­hydrogen hypodiphosphate

The asymmetric unit of the title compound, [Ni(H(2)O)(6)](H(2)P(2)O(6)), contains one-half of the hexa­aqua­nickel(II) cation and one-half of the di­hydrogen hypodiphosphate anion. In the complex cation, the Ni(2+) atom is located on an inversion center and has an octa­hedral coordination sphere. The P—P distance in the centrosymmetric anion is 2.1853 (7) Å. In the crystal, discrete [Ni(H(2)O)(6)](2+) cations and (H(2)P(2)O(6))(2−) anions are stacked in columns parallel to the c axis and are linked into a three-dimensional network by medium-strength O—H⋯O hydrogen bonds.