Bis(3-amino­pyrazine-2-carboxyl­ato-κ²N¹,O)di­aqua­nickel(II) dihydrate

In the title compound, [Ni(C₅H₄N₃O₂)₂(H₂O)₂]·2H₂O, 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.