Cd2C2N3H3SO5 crystallizes in the monoclinic C2/c space group. There are two inequivalent Cd sites. In the first Cd site, Cd(1) is bonded to one N(2), one O(4), two equivalent O(3), and two equivalent O(5) atoms to form CdNO5 octahedra that share  a cornercorner with one Cd(2)N2O4 octahedra, corners with three equivalent S(1)O4 tetrahedra,  an edgeedge with one Cd(2)N2O4 octahedra, and edges with two equivalent Cd(1)NO5 octahedra. The corner-sharing octahedral tilt angles are 65°. The Cd(1)-N(2) bond length is 2.25 Å. The Cd(1)-O(4) bond length is 2.41 Å. There is one shorter (2.36 Å) and one longer (2.49 Å) Cd(1)-O(3) bond length. There is one shorter (2.26 Å) and one longer (2.30 Å) Cd(1)-O(5) bond length. In the second Cd site, Cd(2) is bonded to one N(1), one N(3), one O(1), one O(2), one O(4), and one O(5) atom to form CdN2O4 octahedra that share  a cornercorner with one Cd(1)NO5 octahedra, corners with three equivalent S(1)O4 tetrahedra, and  an edgeedge with one Cd(1)NO5 octahedra. The corner-sharing octahedral tilt angles are 65°. The Cd(2)-N(1) bond length is 2.32 Å. The Cd(2)-N(3) bond length is 2.35 Å. The Cd(2)-O(1) bond length is 2.42 Å. The Cd(2)-O(2) bond length is 2.36 Å. The Cd(2)-O(4) bond length is 2.34 Å. The Cd(2)-O(5) bond length is 2.33 Å. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one N(1), one N(3), and one H(1) atom. The C(1)-N(1) bond length is 1.35 Å. The C(1)-N(3) bond length is 1.33 Å. The C(1)-H(1) bond length is 1.08 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one N(1), one N(2), and one H(2) atom. The C(2)-N(1) bond length is 1.35 Å. The C(2)-N(2) bond length is 1.34 Å. The C(2)-H(2) bond length is 1.08 Å. There are three inequivalent N sites. In the first N site, N(1) is bonded in a 3-coordinate geometry to one Cd(2), one C(1), and one C(2) atom. In the second N site, N(2) is bonded in a distorted trigonal planar geometry to one Cd(1), one C(2), and one N(3) atom. The N(2)-N(3) bond length is 1.37 Å. In the third N site, N(3) is bonded in a 3-coordinate geometry to one Cd(2), one C(1), and one N(2) atom. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(2) atom. In the third H site, H(3) is bonded in a single-bond geometry to one O(5) atom. The H(3)-O(5) bond length is 0.97 Å. S(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SO4 tetrahedra that share corners with three equivalent Cd(2)N2O4 octahedra and corners with three equivalent Cd(1)NO5 octahedra. The corner-sharing octahedral tilt angles range from 46-64°. The S(1)-O(1) bond length is 1.48 Å. The S(1)-O(2) bond length is 1.49 Å. The S(1)-O(3) bond length is 1.50 Å. The S(1)-O(4) bond length is 1.51 Å. There are five inequivalent O sites. In the first O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Cd(1) and one S(1) atom. In the second O site, O(4) is bonded in a 3-coordinate geometry to one Cd(1), one Cd(2), and one S(1) atom. In the third O site, O(5) is bonded in a distorted single-bond geometry to one Cd(2), two equivalent Cd(1), and one H(3) atom. In the fourth O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Cd(2) and one S(1) atom. In the fifth O site, O(2) is bonded in a bent 120 degrees geometry to one Cd(2) and one S(1) atom. Linkers: 3 C1=NC=N[N]1 ,1 [N]1=CN=NC=1. Metal clusters: 8 [Cd]. The MOF has largest included sphere 1.56 A, density 3.56 g/cm3, surface area 2047.34 m2/g, accessible volume 0.04 cm3/g