title: Poly[tetra-aquadi-μ(4)-oxalato-potassium-ytterbium(III)].
abstract: In the title compound, [KYb(C(2)O(4))(2)(H(2)O)(4)](n), the Yb(III) ion lies on a site of [Formula: see text] symmetry in a dodeca-hedral environment defined by eight O atoms from four oxalate ligands. The K atom lies on a different [Formula: see text] axis and is coordinated by four O atoms from four oxalate ligands and four water O atoms. The oxalate ligand has an inversion center at the mid-point of the C-C bond. The metal ions are linked by the oxalate ligands into a three-dimensional framework. O-H⋯O hydrogen bonding is present in the crystal structure.
authors.affiliation: Key Laboratory of Functional Inorganic Materials Chemistry (MOE), School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080,  People's Republic of China.
authors.forename: Feng-Ming
authors.initials: FM
authors.lastname: Zhang
authors.forename: Guang-Feng
authors.initials: GF
authors.lastname: Hou
authors.forename: Peng-Fei
authors.initials: PF
authors.lastname: Yan
authors.forename: Guang-Ming
authors.initials: GM
authors.lastname: Li