Heptaaqua­(3,4,5,6-tetra­chloro­phthalato-κO1)erbium(III) 2-carb­oxy-3,4,5,6-tetra­chloro­benzoate–3,4,5,6-tetra­chloro­phthalic acid–water (1/1/1)

In the three-dimensional tetra­chloro­phthalate-bridged title complex [Er(C8Cl4O4)(H2O)7](C8HCl4O4)·C8H2Cl4O4·H2O, the ErIII ion is coordinated in form of a distorted square antiprism by an O atom of a tetra­chloro­phthalate ligand and by seven water O atoms. Extensive hydrogen bonds establish a layered network structure extending parallel to (001).