Tetra-aqua-bis-(6-chloro-pyridine-3-carboxyl-ato-κO)nickel(II) tetra-hydrate.

In the title compound, [Ni(C(6)H(3)ClNO(2))(2)(H(2)O)(4)]·4H(2)O, the Ni(II) ion is located on an inversion centre and is octa-hedrally coordinated by four O atoms from four water mol-ecules in the equatorial plane and two O atoms of two 6-chloro-3-carboxyl-ate ligands in axial positions. There are also four lattice water molecules present. The organic ligands are bound to the Ni(II) ion in a monodentate manner through a carboxyl-ate O atom. There is one strong intra-molecular O-H⋯O hydrogen bond and six inter-molecular O-H⋯O and O-H⋯N hydrogen-bonding inter-actions in the packing, resulting in a complex three-dimensional network structure.