ErCdC5N2H7SO11 crystallizes in the monoclinic P2_1/c space group. Er(1) is bonded in a 9-coordinate geometry to one O(1), one O(10), one O(11), one O(3), one O(7), one O(8), one O(9), and two equivalent O(2) atoms. The Er(1)-O(1) bond length is 2.41 Å. The Er(1)-O(10) bond length is 2.33 Å. The Er(1)-O(11) bond length is 2.43 Å. The Er(1)-O(3) bond length is 2.26 Å. The Er(1)-O(7) bond length is 2.42 Å. The Er(1)-O(8) bond length is 2.35 Å. The Er(1)-O(9) bond length is 2.48 Å. There is one shorter (2.29 Å) and one longer (2.56 Å) Er(1)-O(2) bond length. Cd(1) is bonded to one N(1), one N(2), one O(1), one O(6), and two equivalent O(4) atoms to form distorted CdN2O4 pentagonal pyramids that share  a cornercorner with one S(1)O4 tetrahedra and  an edgeedge with one Cd(1)N2O4 pentagonal pyramid. The Cd(1)-N(1) bond length is 2.28 Å. The Cd(1)-N(2) bond length is 2.27 Å. The Cd(1)-O(1) bond length is 2.45 Å. The Cd(1)-O(6) bond length is 2.38 Å. There is one shorter (2.29 Å) and one longer (2.42 Å) Cd(1)-O(4) bond length. There are five inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one N(1), one N(2), and one H(1) atom. The C(1)-N(1) bond length is 1.34 Å. The C(1)-N(2) bond length is 1.34 Å. The C(1)-H(1) bond length is 1.09 Å. In the second C site, C(2) is bonded in a distorted single-bond geometry to one C(3), one C(4), and one N(2) atom. The C(2)-C(3) bond length is 1.40 Å. The C(2)-C(4) bond length is 1.45 Å. The C(2)-N(2) bond length is 1.38 Å. In the third C site, C(3) is bonded in a distorted single-bond geometry to one C(2), one C(5), and one N(1) atom. The C(3)-C(5) bond length is 1.48 Å. The C(3)-N(1) bond length is 1.37 Å. In the fourth C site, C(4) is bonded in a distorted bent 120 degrees geometry to one C(2), one O(1), and one O(2) atom. The C(4)-O(1) bond length is 1.28 Å. The C(4)-O(2) bond length is 1.28 Å. In the fifth C site, C(5) is bonded in a distorted bent 120 degrees geometry to one C(3), one O(3), and one O(4) atom. The C(5)-O(3) bond length is 1.26 Å. The C(5)-O(4) bond length is 1.28 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded in a distorted trigonal planar geometry to one Cd(1), one C(1), and one C(3) atom. In the second N site, N(2) is bonded in a distorted trigonal planar geometry to one Cd(1), one C(1), and one C(2) atom. There are seven 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 O(9) atom. The H(2)-O(9) bond length is 1.00 Å. In the third H site, H(3) is bonded in a single-bond geometry to one O(9) atom. The H(3)-O(9) bond length is 0.98 Å. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(10) atom. The H(4)-O(10) bond length is 0.97 Å. In the fifth H site, H(5) is bonded in a distorted single-bond geometry to one O(10) and one O(7) atom. The H(5)-O(10) bond length is 1.00 Å. The H(5)-O(7) bond length is 1.65 Å. In the sixth H site, H(6) is bonded in a single-bond geometry to one O(11) atom. The H(6)-O(11) bond length is 0.98 Å. In the seventh H site, H(7) is bonded in a single-bond geometry to one O(11) atom. The H(7)-O(11) bond length is 0.99 Å. S(1) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form SO4 tetrahedra that share  a cornercorner with one Cd(1)N2O4 pentagonal pyramid. The S(1)-O(5) bond length is 1.48 Å. The S(1)-O(6) bond length is 1.50 Å. The S(1)-O(7) bond length is 1.51 Å. The S(1)-O(8) bond length is 1.48 Å. There are eleven inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Er(1), one Cd(1), and one C(4) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Er(1) and one C(4) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Er(1) and one C(5) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Cd(1) and one C(5) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to one S(1) atom. In the sixth O site, O(6) is bonded in a 1-coordinate geometry to one Cd(1) and one S(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Er(1), one H(5), and one S(1) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Er(1) and one S(1) atom. In the ninth O site, O(9) is bonded in a water-like geometry to one Er(1), one H(2), and one H(3) atom. In the tenth O site, O(10) is bonded in a distorted water-like geometry to one Er(1), one H(4), and one H(5) atom. In the eleventh O site, O(11) is bonded in a water-like geometry to one Er(1), one H(6), and one H(7) atom. Linkers: 3 [O]C(=O)C1=C(C([O])=O)N=C[N]1 ,1 [O]C(=O)[C]1N=CN=C1C([O])=O. Metal clusters: 4 [Er] ,4 [Cd]. The MOF has largest included sphere 2.47 A, density 3.21 g/cm3, surface area 1861.58 m2/g, accessible volume 0.05 cm3/g