Cd2C7NH5O6 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Cd sites. In the first Cd site, Cd(1) is bonded to one N(1), one O(2), one O(3), one O(4), and two equivalent O(1) atoms to form distorted CdNO5 octahedra that share corners with three equivalent Cd(2)O6 pentagonal pyramids,  an edgeedge with one Cd(1)NO5 octahedra, and  an edgeedge with one Cd(2)O6 pentagonal pyramid. The Cd(1)-N(1) bond length is 2.35 Å. The Cd(1)-O(2) bond length is 2.29 Å. The Cd(1)-O(3) bond length is 2.35 Å. The Cd(1)-O(4) bond length is 2.54 Å. There is one shorter (2.27 Å) and one longer (2.28 Å) Cd(1)-O(1) bond length. In the second Cd site, Cd(2) is bonded to one O(1), one O(3), one O(5), one O(6), and two equivalent O(2) atoms to form distorted CdO6 pentagonal pyramids that share corners with three equivalent Cd(1)NO5 octahedra, corners with two equivalent Cd(2)O6 pentagonal pyramids, and  an edgeedge with one Cd(1)NO5 octahedra. The corner-sharing octahedral tilt angles range from 54-71°. The Cd(2)-O(1) bond length is 2.29 Å. The Cd(2)-O(3) bond length is 2.38 Å. The Cd(2)-O(5) bond length is 2.42 Å. The Cd(2)-O(6) bond length is 2.46 Å. There is one shorter (2.25 Å) and one longer (2.35 Å) Cd(2)-O(2) bond length. There are seven inequivalent C sites. In the first C site, C(1) is bonded in a distorted single-bond geometry to one N(1) atom. The C(1)-N(1) bond length is 1.35 Å. In the second C site, C(2) is bonded in a distorted single-bond geometry to one C(3) and one H(3) atom. The C(2)-C(3) bond length is 1.40 Å. The C(2)-H(3) bond length is 1.09 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one C(2), one C(4), and one C(7) atom. The C(3)-C(4) bond length is 1.40 Å. The C(3)-C(7) bond length is 1.50 Å. In the fourth C site, C(4) is bonded in a distorted single-bond geometry to one C(3), one C(5), and one H(4) atom. The C(4)-C(5) bond length is 1.39 Å. The C(4)-H(4) bond length is 1.09 Å. In the fifth C site, C(5) is bonded in a distorted trigonal planar geometry to one C(4), one N(1), and one H(5) atom. The C(5)-N(1) bond length is 1.34 Å. The C(5)-H(5) bond length is 1.09 Å. In the sixth C site, C(6) is bonded in a distorted bent 120 degrees geometry to one O(3) and one O(4) atom. The C(6)-O(3) bond length is 1.28 Å. The C(6)-O(4) bond length is 1.26 Å. In the seventh C site, C(7) is bonded in a distorted bent 120 degrees geometry to one C(3), one O(5), and one O(6) atom. The C(7)-O(5) bond length is 1.27 Å. The C(7)-O(6) bond length is 1.28 Å. N(1) is bonded in a distorted trigonal planar geometry to one Cd(1), one C(1), and one C(5) atom. There are five inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(1) atom. The H(1)-O(1) bond length is 0.99 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(2) atom. The H(2)-O(2) bond length is 0.98 Å. In the third H site, H(3) is bonded in a single-bond geometry to one C(2) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(4) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(5) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Cd(2), two equivalent Cd(1), and one H(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Cd(1), two equivalent Cd(2), and one H(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Cd(1), one Cd(2), and one C(6) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Cd(1) and one C(6) atom. In the fifth O site, O(5) is bonded in a distorted L-shaped geometry to one Cd(2) and one C(7) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Cd(2) and one C(7) atom. Linkers: 4 [O]C(=O)c1ccnc(C([O])=O)c1. Metal clusters: 8 [Cd]. The MOF has largest included sphere 1.92 A, density 2.97 g/cm3, surface area 2308.93 m2/g, accessible volume 0.09 cm3/g