Poly[[hexa­aqua­(μ(2)-fumarato-κ(4) O (1),O (1′):O (4),O (4′))bis­(μ(3)-maleato-κ(4) O (1),O (1′):O (4):O (4′))disamarium(III)] hexa­hydrate]

In the title coordination polymer, {[Sm(2)(C(4)H(2)O(4))(3)(H(2)O)(6)]·6H(2)O}(n), the Sm(III) ion is nine-coordinated by four O atoms from three different maleate ligands, two O atoms from one fumarate ligand and three O atoms from three water mol­ecules. The fumarate ligand lies on an inversion center. Adjacent Sm(III) ions are bridged by the maleate and fumarate ligands, forming a layer parallel to (011). The layers are further linked by inter­molecular O—H⋯O hydrogen bonds into a three-dimensional supra­molecular network.