Bis(guanidinium) tris­(pyridine-2,6-dicarboxyl­ato-κ³O²,N,O⁶)zirconate(II) tetra­hydrate

In the title complex, (CH₆N₃)₂[Zr(C₇H₃NO₄)₃]·4H₂O, the Zr^IV ion lies on a twofold rotation axes and is coordinated by six O and three N atoms of three tridentate pyridine-2,6-dicarboxyl­ate ligands, forming a slightly distorted tricapped trigonal–prismatic geometry. In the crystal, O—H...O and N—H...O hydrogen bonds link the components into a three-dimensional network.