Diaqua­bis­(4-formyl­benzoato-κO (1))bis­(nicotinamide-κN (1))nickel(II)

In the title complex, [Ni(C(8)H(5)O(3))(2)(C(6)H(6)N(2)O)(2)(H(2)O)(2)], the Ni(II) cation is located on an inversion center and is coordinated by two 4-formyl­benzoate (FB) anions, two nicotinamide (NA) ligands and two water mol­ecules. The four O atoms in the equatorial plane around the Ni(II) cation form a slightly distorted square-planar arrangement, while the slightly distorted octa­hedral coordination is completed by the two N atoms of the NA ligands in the axial positions. The dihedral angle between the carboxyl­ate group and the adjacent benzene ring is 23.67 (8)°, while the pyridine and benzene rings are oriented at an angle of 89.04 (4)°. The coordinating water mol­ecule links with the carboxyl­ate group via an O—H⋯O hydrogen bond. In the crystal, N—H⋯O, O—H⋯O and weak C—H⋯O hydrogen bonds link the mol­ecules into a three-dimensional supra­molecular network. π–π contacts between benzene rings [centroid–centroid distance = 3.8414 (7) Å] may further stabilize the structure. A weak C—H⋯π inter­action also occurs.