CdC5N2H7O5 crystallizes in the monoclinic P2_1/c space group. Cd(1) is bonded in a 7-coordinate geometry to one N(1), one N(2), one O(1), one O(2), one O(3), one O(4), and one O(5) atom. The Cd(1)-N(1) bond length is 2.30 Å. The Cd(1)-N(2) bond length is 2.35 Å. The Cd(1)-O(1) bond length is 2.67 Å. The Cd(1)-O(2) bond length is 2.39 Å. The Cd(1)-O(3) bond length is 2.30 Å. The Cd(1)-O(4) bond length is 2.79 Å. The Cd(1)-O(5) bond length is 2.36 Å. There are five inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one C(2), one O(1), and one O(2) atom. The C(1)-C(2) bond length is 1.50 Å. The C(1)-O(1) bond length is 1.28 Å. The C(1)-O(2) bond length is 1.27 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one C(1), one C(4), and one C(5) atom. The C(2)-C(4) bond length is 1.41 Å. The C(2)-C(5) bond length is 1.40 Å. In the third C site, C(3) is bonded in a distorted bent 120 degrees geometry to one C(4), one O(3), and one O(4) atom. The C(3)-C(4) bond length is 1.50 Å. The C(3)-O(3) bond length is 1.29 Å. The C(3)-O(4) bond length is 1.25 Å. In the fourth C site, C(4) is bonded in a trigonal planar geometry to one C(2), one C(3), and one C(5) atom. The C(4)-C(5) bond length is 1.40 Å. In the fifth C site, C(5) is bonded in a distorted single-bond geometry to one C(2), one C(4), and one H(2) atom. The C(5)-H(2) bond length is 1.09 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded in a distorted water-like geometry to one Cd(1), one H(3), and one H(4) atom. The N(1)-H(3) bond length is 1.02 Å. The N(1)-H(4) bond length is 1.04 Å. In the second N site, N(2) is bonded in a distorted water-like geometry to one Cd(1), one H(1), and one H(5) atom. The N(2)-H(1) bond length is 1.03 Å. The N(2)-H(5) bond length is 1.03 Å. There are seven inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one N(2) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(5) atom. In the third H site, H(3) is bonded in a single-bond geometry to one N(1) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one N(1) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one N(2) atom. In the sixth H site, H(6) is bonded in a linear geometry to one O(1) and one O(5) atom. The H(6)-O(1) bond length is 1.57 Å. The H(6)-O(5) bond length is 1.02 Å. In the seventh H site, H(7) is bonded in a single-bond geometry to one O(5) atom. The H(7)-O(5) bond length is 0.97 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Cd(1), one C(1), and one H(6) atom. In the second O site, O(2) is bonded in a distorted water-like geometry to one Cd(1) and one C(1) atom. In the third O site, O(3) is bonded in a distorted water-like geometry to one Cd(1) and one C(3) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one Cd(1) and one C(3) atom. In the fifth O site, O(5) is bonded in a distorted water-like geometry to one Cd(1), one H(6), and one H(7) atom. Linkers: 2 [O]C(=O)c1cc(C([O])=O)c(C([O])=O)cc1C([O])=O. Metal clusters: 4 [Cd]. The MOF has largest included sphere 2.71 A, density 2.12 g/cm3, surface area 3158.81 m2/g, accessible volume 0.13 cm3/g