GdC5H4O6 crystallizes in the orthorhombic Fddd space group. Gd(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Both Gd(1)-O(1) bond lengths are 2.49 Å. Both Gd(1)-O(2) bond lengths are 2.35 Å. Both Gd(1)-O(3) bond lengths are 2.44 Å. There are three inequivalent C sites. In the first C site, C(3) is bonded in a distorted bent 120 degrees geometry to two equivalent O(3) atoms. Both C(3)-O(3) bond lengths are 1.25 Å. In the second C site, C(1) is bonded in a distorted trigonal planar geometry to one C(2), one O(1), and one O(2) atom. The C(1)-C(2) bond length is 1.49 Å. The C(1)-O(1) bond length is 1.25 Å. The C(1)-O(2) bond length is 1.26 Å. In the third C site, C(2) is bonded in a distorted water-like geometry to one C(1), one H(1), and one H(2) atom. The C(2)-H(1) bond length is 0.97 Å. The C(2)-H(2) bond length is 0.97 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(2) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(2) atom. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted water-like geometry to one Gd(1) and one C(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Gd(1) and one C(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Gd(1) and one C(3) atom. Linkers: 4 [O]C(=O)CCC([O])=O ,2 [O]C(=O)C([O])=O. Metal clusters: 4 [Gd]. The MOF has largest included sphere 4.31 A, density 2.06 g/cm3, surface area 2426.06 m2/g, accessible volume 0.24 cm3/g