Cd5C20H10(N4O9)2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Cd sites. In the first Cd site, Cd(1) is bonded to one N(1), one N(3), one O(5), one O(8), and two equivalent O(2) atoms to form distorted edge-sharing CdN2O4 pentagonal pyramids. The Cd(1)-N(1) bond length is 2.28 Å. The Cd(1)-N(3) bond length is 2.27 Å. The Cd(1)-O(5) bond length is 2.47 Å. The Cd(1)-O(8) bond length is 2.41 Å. There is one shorter (2.28 Å) and one longer (2.44 Å) Cd(1)-O(2) bond length. In the second Cd site, Cd(2) is bonded in an octahedral geometry to two equivalent O(1), two equivalent O(3), and two equivalent O(9) atoms. Both Cd(2)-O(1) bond lengths are 2.23 Å. Both Cd(2)-O(3) bond lengths are 2.22 Å. Both Cd(2)-O(9) bond lengths are 2.47 Å. In the third Cd site, Cd(3) is bonded in a 6-coordinate geometry to one N(2), one N(4), one O(5), one O(8), and two equivalent O(4) atoms. The Cd(3)-N(2) bond length is 2.28 Å. The Cd(3)-N(4) bond length is 2.24 Å. The Cd(3)-O(5) bond length is 2.25 Å. The Cd(3)-O(8) bond length is 2.69 Å. There is one shorter (2.32 Å) and one longer (2.40 Å) Cd(3)-O(4) bond length. There are ten 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(1) atom. The C(2)-C(3) bond length is 1.41 Å. The C(2)-C(4) bond length is 1.48 Å. The C(2)-N(1) 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(2) atom. The C(3)-C(5) bond length is 1.49 Å. The C(3)-N(2) bond length is 1.38 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 1.26 Å. The C(4)-O(2) bond length is 1.29 Å. In the fifth C site, C(5) is bonded in a bent 120 degrees geometry to one C(3), one O(3), and one O(4) atom. The C(5)-O(3) bond length is 1.27 Å. The C(5)-O(4) bond length is 1.28 Å. In the sixth C site, C(6) is bonded in a trigonal planar geometry to one N(3), one N(4), and one H(2) atom. The C(6)-N(3) bond length is 1.35 Å. The C(6)-N(4) bond length is 1.34 Å. The C(6)-H(2) bond length is 1.08 Å. In the seventh C site, C(7) is bonded in a distorted single-bond geometry to one C(8), one C(9), and one N(3) atom. The C(7)-C(8) bond length is 1.40 Å. The C(7)-C(9) bond length is 1.47 Å. The C(7)-N(3) bond length is 1.37 Å. In the eighth C site, C(8) is bonded in a distorted single-bond geometry to one C(10), one C(7), and one N(4) atom. The C(8)-C(10) bond length is 1.47 Å. The C(8)-N(4) bond length is 1.37 Å. In the ninth C site, C(9) is bonded in a distorted bent 120 degrees geometry to one C(7), one O(5), and one O(6) atom. The C(9)-O(5) bond length is 1.28 Å. The C(9)-O(6) bond length is 1.27 Å. In the tenth C site, C(10) is bonded in a distorted bent 120 degrees geometry to one C(8), one O(7), and one O(8) atom. The C(10)-O(7) bond length is 1.31 Å. The C(10)-O(8) bond length is 1.26 Å. There are four 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(2) atom. In the second N site, N(2) is bonded in a distorted trigonal planar geometry to one Cd(3), one C(1), and one C(3) atom. In the third N site, N(3) is bonded in a distorted trigonal planar geometry to one Cd(1), one C(6), and one C(7) atom. In the fourth N site, N(4) is bonded in a trigonal planar geometry to one Cd(3), one C(6), and one C(8) atom. There are five 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(6) atom. In the third H site, H(3) is bonded in a linear geometry to one O(6) and one O(7) atom. The H(3)-O(6) bond length is 1.41 Å. The H(3)-O(7) bond length is 1.08 Å. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(9) atom. The H(4)-O(9) bond length is 0.97 Å. In the fifth H site, H(5) is bonded in a single-bond geometry to one O(9) atom. The H(5)-O(9) bond length is 0.97 Å. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Cd(2) and one C(4) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Cd(1) and one C(4) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Cd(2) and one C(5) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Cd(3) and one C(5) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Cd(1), one Cd(3), and one C(9) atom. In the sixth O site, O(6) is bonded in a water-like geometry to one C(9) and one H(3) atom. In the seventh O site, O(7) is bonded in a water-like geometry to one C(10) and one H(3) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one Cd(1), one Cd(3), and one C(10) atom. In the ninth O site, O(9) is bonded in a distorted water-like geometry to one Cd(2), one H(4), and one H(5) atom. Linkers: 4 [O]C(=O)C1=C(C(=O)O)[N]C=N1 ,4 [O]C(=O)[C]1N=CN=C1C([O])=O. Metal clusters: 10 [Cd]. The MOF has largest included sphere 3.89 A, density 2.21 g/cm3, surface area 2851.26 m2/g, accessible volume 0.17 cm3/g