CdC7NH3O4 crystallizes in the monoclinic P2_1/c space group. Cd(1) is bonded to one N(1), one O(1), one O(2), one O(3), and two equivalent O(4) atoms to form edge-sharing CdNO5 octahedra. The Cd(1)-N(1) bond length is 2.34 Å. The Cd(1)-O(1) bond length is 2.30 Å. The Cd(1)-O(2) bond length is 2.25 Å. The Cd(1)-O(3) bond length is 2.42 Å. There is one shorter (2.29 Å) and one longer (2.50 Å) Cd(1)-O(4) bond length. There are seven inequivalent C sites. In the first C site, C(5) is bonded in a distorted single-bond geometry to one C(4), one C(6), and one H(2) atom. The C(5)-C(4) bond length is 1.40 Å. The C(5)-C(6) bond length is 1.40 Å. The C(5)-H(2) bond length is 1.09 Å. In the second C site, C(6) is bonded in a distorted trigonal planar geometry to one C(5), one N(1), and one H(3) atom. The C(6)-N(1) bond length is 1.34 Å. The C(6)-H(3) bond length is 1.09 Å. In the third C site, C(7) is bonded in a distorted bent 120 degrees geometry to one C(4), one O(3), and one O(4) atom. The C(7)-C(4) bond length is 1.50 Å. The C(7)-O(3) bond length is 1.26 Å. The C(7)-O(4) bond length is 1.29 Å. In the fourth 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 1.52 Å. The C(1)-O(1) bond length is 1.27 Å. The C(1)-O(2) bond length is 1.26 Å. In the fifth C site, C(2) is bonded in a distorted trigonal planar geometry to one C(1), one C(3), and one N(1) atom. The C(2)-C(3) bond length is 1.39 Å. The C(2)-N(1) bond length is 1.35 Å. In the sixth C site, C(3) is bonded in a distorted single-bond geometry to one C(2), one C(4), and one H(1) atom. The C(3)-C(4) bond length is 1.40 Å. The C(3)-H(1) bond length is 1.09 Å. In the seventh C site, C(4) is bonded in a trigonal planar geometry to one C(3), one C(5), and one C(7) atom. N(1) is bonded in a distorted trigonal planar geometry to one Cd(1), one C(2), and one C(6) atom. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(3) 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 C(6) atom. There are four inequivalent O sites. In the first O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Cd(1) and one C(7) atom. In the second O site, O(1) is bonded in a bent 120 degrees geometry to one Cd(1) and one C(1) atom. In the third O site, O(2) is bonded in a bent 150 degrees geometry to one Cd(1) and one C(1) atom. In the fourth O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Cd(1) and one C(7) atom. Linkers: 4 [O]C(=O)c1ccnc(C([O])=O)c1. Metal clusters: 4 [Cd]. The MOF has largest included sphere 1.77 A, density 2.63 g/cm3, surface area 2505.29 m2/g, accessible volume 0.08 cm3/g