Mg3C32H26(N2O9)2 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(1), one O(3), one O(5), one O(6), and one O(9) atom to form corner-sharing MgO5 square pyramids. The corner-sharing octahedral tilt angles are 65°. The Mg(1)-O(1) bond length is 2.03 Å. The Mg(1)-O(3) bond length is 2.15 Å. The Mg(1)-O(5) bond length is 2.09 Å. The Mg(1)-O(6) bond length is 2.08 Å. The Mg(1)-O(9) bond length is 2.10 Å. In the second Mg site, Mg(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(7) atoms to form corner-sharing MgO6 octahedra. Both Mg(2)-O(2) bond lengths are 2.05 Å. Both Mg(2)-O(3) bond lengths are 2.11 Å. Both Mg(2)-O(7) bond lengths are 2.01 Å. There are sixteen inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one C(2), one O(1), and one O(2) atom. The C(1)-C(2) bond length is 1.51 Å. The C(1)-O(1) bond length is 1.25 Å. The C(1)-O(2) bond length is 1.25 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one C(1), one C(3), and one C(8) atom. The C(2)-C(3) bond length is 1.39 Å. The C(2)-C(8) bond length is 1.39 Å. In the third C site, C(3) is bonded in a distorted single-bond geometry to one C(2), one C(4), and one H(6) atom. The C(3)-C(4) bond length is 1.38 Å. The C(3)-H(6) bond length is 0.93 Å. In the fourth C site, C(4) is bonded in a distorted trigonal planar geometry to one C(3), one C(5), and one N(1) atom. The C(4)-C(5) bond length is 1.38 Å. The C(4)-N(1) bond length is 1.47 Å. In the fifth C site, C(5) is bonded in a single-bond geometry to one C(4), one C(6), and one H(7) atom. The C(5)-C(6) bond length is 1.39 Å. The C(5)-H(7) 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 1.51 Å. The C(6)-C(8) bond length is 1.39 Å. In the seventh C site, C(7) is bonded in a distorted bent 120 degrees geometry to one C(6), one O(4), and one O(5) atom. The C(7)-O(4) bond length is 1.25 Å. The C(7)-O(5) bond length is 1.26 Å. In the eighth C site, C(8) is bonded in a distorted single-bond geometry to one C(2), one C(6), and one H(8) atom. The C(8)-H(8) bond length is 0.93 Å. In the ninth C site, C(9) is bonded in a bent 120 degrees geometry to one C(10), one O(6), and one O(7) atom. The C(9)-C(10) bond length is 1.50 Å. The C(9)-O(6) bond length is 1.26 Å. The C(9)-O(7) bond length is 1.24 Å. In the tenth C site, C(10) is bonded in a trigonal planar geometry to one C(11), one C(16), and one C(9) atom. The C(10)-C(11) bond length is 1.39 Å. The C(10)-C(16) bond length is 1.39 Å. In the eleventh C site, C(11) is bonded in a single-bond geometry to one C(10), one C(12), and one H(9) atom. The C(11)-C(12) bond length is 1.39 Å. The C(11)-H(9) bond length is 0.93 Å. In the twelfth C site, C(12) is bonded in a trigonal planar geometry to one C(11), one C(13), and one C(14) atom. The C(12)-C(13) bond length is 1.50 Å. The C(12)-C(14) bond length is 1.39 Å. In the thirteenth C site, C(13) is bonded in a distorted bent 120 degrees geometry to one C(12), one O(8), and one O(9) atom. The C(13)-O(8) bond length is 1.23 Å. The C(13)-O(9) bond length is 1.27 Å. In the fourteenth C site, C(14) is bonded in a single-bond geometry to one C(12), one C(15), and one H(10) atom. The C(14)-C(15) bond length is 1.39 Å. The C(14)-H(10) bond length is 0.93 Å. In the fifteenth C site, C(15) is bonded in a distorted trigonal planar geometry to one C(14), one C(16), and one N(2) atom. The C(15)-C(16) bond length is 1.39 Å. The C(15)-N(2) bond length is 1.41 Å. In the sixteenth C site, C(16) is bonded in a distorted single-bond geometry to one C(10), one C(15), and one H(11) atom. The C(16)-H(11) bond length is 0.93 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded in a distorted water-like geometry to one C(4), one H(2), and one H(3) atom. The N(1)-H(2) bond length is 0.88 Å. The N(1)-H(3) bond length is 0.86 Å. In the second N site, N(2) is bonded in a distorted bent 120 degrees geometry to one C(15), one H(4), and one H(5) atom. The N(2)-H(4) bond length is 0.88 Å. The N(2)-H(5) bond length is 0.91 Å. There are thirteen inequivalent H sites. In the first H site, H(1) is bonded in a distorted single-bond geometry to one O(8) atom. The H(1)-O(8) bond length is 0.82 Å. In the second H site, H(2) is bonded in a single-bond geometry to one N(1) atom. In the third H site, H(3) is bonded in a single-bond geometry to one N(1) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one N(2) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one N(2) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one C(3) atom. In the seventh H site, H(7) is bonded in a single-bond geometry to one C(5) atom. In the eighth H site, H(8) is bonded in a single-bond geometry to one C(8) atom. In the ninth H site, H(9) is bonded in a single-bond geometry to one C(11) atom. In the tenth H site, H(10) is bonded in a single-bond geometry to one C(14) atom. In the eleventh H site, H(11) is bonded in a single-bond geometry to one C(16) atom. In the twelfth H site, H(12) is bonded in a single-bond geometry to one O(3) atom. The H(12)-O(3) bond length is 0.85 Å. In the thirteenth H site, H(13) is bonded in a single-bond geometry to one O(3) atom. The H(13)-O(3) bond length is 0.83 Å. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Mg(1) and one C(1) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Mg(2) and one C(1) atom. In the third O site, O(3) is bonded in a distorted water-like geometry to one Mg(1), one Mg(2), one H(12), and one H(13) atom. In the fourth O site, O(9) is bonded in a distorted bent 120 degrees geometry to one Mg(1) and one C(13) atom. In the fifth O site, O(4) is bonded in a single-bond geometry to one C(7) atom. In the sixth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Mg(1) and one C(7) atom. In the seventh O site, O(6) is bonded in a bent 120 degrees geometry to one Mg(1) and one C(9) atom. In the eighth O site, O(7) is bonded in a bent 150 degrees geometry to one Mg(2) and one C(9) atom. In the ninth O site, O(8) is bonded in a water-like geometry to one C(13) and one H(1) atom. Linkers: 4 Nc1cc(C([O])=O)cc(C(=O)O)c1 ,4 Nc1cc(C([O])=O)cc(C([O])=O)c1. Metal clusters: 2 O.O.O=[C]O.O=[C]O.O=[C]O[Mg]O[C]O[Mg]O[C]O[Mg]O[C]=O.[O][C]=O.[O][C]=O. RCSR code: bcu. The MOF has largest included sphere 7.25 A, density 0.96 g/cm3, surface area 4344.94 m2/g, accessible volume 0.48 cm3/g