Bis(3-amino­pyrazine-2-carboxyl­ato-κ(2) N (1),O)di­aqua­nickel(II) dihydrate

In the title compound, [Ni(C(5)H(4)N(3)O(2))(2)(H(2)O)(2)]·2H(2)O, the Ni(II) ion lies on an inversion center and is coordinated in an slightly distorted octa­hedral environment by two N,O-chelating 3-amino­pyrazine-2-carboxyl­ate (APZC) ligands in the equatorial plane and two trans-axial aqua ligands. In the crystal, O—H⋯O, N—H⋯O and O—H⋯N hydrogen bonds involving the solvent water mol­ecules, aqua and APZC ligands form layers parallel to (010). These layers are linked further via O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds involving the axial aqua ligands, amino groups and the carboxyl­ate groups of the APZC ligands, forming a three-dimensional network.