Mg3C32H24(N2O9)2 crystallizes in the orthorhombic Pnnm space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(5), two equivalent O(1), and two equivalent O(3) atoms to form distorted corner-sharing MgO5 square pyramids. The corner-sharing octahedral tilt angles are 65°. The Mg(1)-O(5) bond length is 2.16 Å. Both Mg(1)-O(1) bond lengths are 2.06 Å. Both Mg(1)-O(3) bond lengths are 2.05 Å. In the second Mg site, Mg(2) is bonded to two equivalent O(5) and four equivalent O(4) atoms to form corner-sharing MgO6 octahedra. Both Mg(2)-O(5) bond lengths are 2.11 Å. All Mg(2)-O(4) bond lengths are 2.02 Å. There are eight inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one C(3), one C(4), and one C(7) atom. The C(1)-C(3) bond length is 1.38 Å. The C(1)-C(4) bond length is 1.51 Å. The C(1)-C(7) bond length is 1.39 Å. In the second C site, C(2) is bonded in a distorted trigonal planar geometry to one C(3), one C(5), and one N(1) atom. The C(2)-C(3) bond length is 1.40 Å. The C(2)-C(5) bond length is 1.38 Å. The C(2)-N(1) bond length is 1.40 Å. In the third C site, C(3) is bonded in a single-bond geometry to one C(1), one C(2), and one H(1) atom. The C(3)-H(1) bond length is 0.93 Å. In the fourth C site, C(4) is bonded in a distorted bent 120 degrees geometry to one C(1), 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 1.26 Å. In the fifth C site, C(5) is bonded in a distorted single-bond geometry to one C(2), one C(6), and one H(2) atom. The C(5)-C(6) bond length is 1.39 Å. The C(5)-H(2) bond length is 0.93 Å. In the sixth C site, C(6) is bonded in a trigonal planar geometry to one C(5), one C(7), and one C(8) atom. The C(6)-C(7) bond length is 1.39 Å. The C(6)-C(8) bond length is 1.50 Å. In the seventh C site, C(7) is bonded in a distorted single-bond geometry to one C(1), one C(6), and one H(3) atom. The C(7)-H(3) bond length is 0.93 Å. In the eighth C site, C(8) is bonded in a bent 120 degrees geometry to one C(6), one O(3), and one O(4) atom. The C(8)-O(3) bond length is 1.24 Å. The C(8)-O(4) bond length is 1.24 Å. N(1) is bonded in a distorted trigonal planar geometry to one C(2), one H(4), and one H(5) atom. The N(1)-H(4) bond length is 0.86 Å. The N(1)-H(5) bond length is 0.86 Å. There are six 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(7) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one N(1) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one N(1) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one O(5) atom. The H(6)-O(5) bond length is 0.84 Å. There are five inequivalent O sites. In the first O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Mg(1) and one C(8) atom. In the second O site, O(4) is bonded in a bent 150 degrees geometry to one Mg(2) and one C(8) atom. In the third O site, O(5) is bonded in a distorted water-like geometry to one Mg(1), one Mg(2), and two equivalent H(6) atoms. In the fourth O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Mg(1) and one C(4) atom. In the fifth O site, O(2) is bonded in a single-bond geometry to one C(4) atom. Linkers: 8 Nc1cc(C([O])=O)cc(C([O])=O)c1. Metal clusters: 2 O.O.O=[C]O[Mg]O[C]O[Mg]O[C]O[Mg]O[C]=O.[O][C]=O.[O][C]=O.[O][C]=O.[O][C]=O. RCSR code: bcu. The MOF has largest included sphere 7.37 A, density 0.95 g/cm3, surface area 4661.68 m2/g, accessible volume 0.58 cm3/g