GdC4N3H2O5 crystallizes in the trigonal P3_221 space group. Gd(1) is bonded in a 9-coordinate geometry to one N(2), two equivalent N(1), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. The Gd(1)-N(2) bond length is 2.53 Å. Both Gd(1)-N(1) bond lengths are 2.58 Å. Both Gd(1)-O(1) bond lengths are 2.56 Å. Both Gd(1)-O(2) bond lengths are 2.30 Å. Both Gd(1)-O(3) bond lengths are 2.41 Å. There are two inequivalent C sites. In the first C site, C(1) is bonded in a distorted single-bond geometry to one C(1), one C(2), and one N(1) atom. The C(1)-C(1) bond length is 1.41 Å. The C(1)-C(2) bond length is 1.49 Å. The C(1)-N(1) bond length is 1.36 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one C(1), one O(2), and one O(3) atom. The C(2)-O(2) bond length is 1.27 Å. The C(2)-O(3) bond length is 1.27 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded in a distorted trigonal planar geometry to one Gd(1), one C(1), and one N(2) atom. The N(1)-N(2) bond length is 1.33 Å. In the second N site, N(2) is bonded in a trigonal planar geometry to one Gd(1) and two equivalent N(1) atoms. H(1) is bonded in a single-bond geometry to one O(1) atom. The H(1)-O(1) bond length is 0.98 Å. There are three inequivalent O sites. In the first O site, O(2) is bonded in a bent 150 degrees geometry to one Gd(1) and one C(2) atom. In the second O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Gd(1) and one C(2) atom. In the third O site, O(1) is bonded in a water-like geometry to two equivalent Gd(1) and two equivalent H(1) atoms. Linkers: 1 [O]C(=O)[C]1N=NN=C1C([O])=O ,2 [O]C(=O)C1=C(C([O])=O)N=N[N]1. Metal clusters: 3 [Gd]. The MOF has largest included sphere 3.36 A, density 2.71 g/cm3, surface area 1763.92 m2/g, accessible volume 0.11 cm3/g