MgC7NH3O4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a rectangular see-saw-like geometry to one N(2), one O(1), one O(6), and one O(7) atom. The Mg(1)-N(2) bond length is 2.24 Å. The Mg(1)-O(1) bond length is 2.04 Å. The Mg(1)-O(6) bond length is 2.03 Å. The Mg(1)-O(7) bond length is 2.07 Å. In the second Mg site, Mg(2) is bonded in a trigonal bipyramidal geometry to one O(2), one O(3), one O(4), one O(5), and one O(8) atom. The Mg(2)-O(2) bond length is 2.03 Å. The Mg(2)-O(3) bond length is 2.01 Å. The Mg(2)-O(4) bond length is 1.99 Å. The Mg(2)-O(5) bond length is 2.02 Å. The Mg(2)-O(8) bond length is 2.07 Å. There are fourteen inequivalent C sites. In the first C site, C(1) is bonded in a 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(7) atom. The C(2)-C(3) bond length is 1.39 Å. The C(2)-C(7) bond length is 1.39 Å. In the third C site, C(3) is bonded in a distorted bent 120 degrees geometry to one C(2), one N(1), and one H(1) atom. The C(3)-N(1) bond length is 1.33 Å. The C(3)-H(1) bond length is 0.93 Å. In the fourth C site, C(4) is bonded in a distorted trigonal planar geometry to one C(5), one N(1), and one H(2) atom. The C(4)-C(5) bond length is 1.39 Å. The C(4)-N(1) bond length is 1.34 Å. The C(4)-H(2) bond length is 0.93 Å. In the fifth C site, C(5) is bonded in a trigonal planar geometry to one C(4), one C(6), and one C(7) atom. The C(5)-C(6) bond length is 1.50 Å. The C(5)-C(7) bond length is 1.38 Å. In the sixth C site, C(6) is bonded in a distorted bent 120 degrees geometry to one C(5), one O(3), and one O(4) atom. The C(6)-O(3) bond length is 1.23 Å. The C(6)-O(4) bond length is 1.25 Å. In the seventh C site, C(7) is bonded in a distorted single-bond geometry to one C(2), one C(5), 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(9), one O(5), and one O(6) atom. The C(8)-C(9) bond length is 1.50 Å. The C(8)-O(5) bond length is 1.25 Å. The C(8)-O(6) bond length is 1.25 Å. In the ninth C site, C(9) is bonded in a trigonal planar geometry to one C(10), one C(14), and one C(8) atom. The C(9)-C(10) bond length is 1.39 Å. The C(9)-C(14) bond length is 1.38 Å. In the tenth C site, C(10) is bonded in a distorted bent 120 degrees geometry to one C(9), one N(2), and one H(4) atom. The C(10)-N(2) bond length is 1.34 Å. The C(10)-H(4) bond length is 0.93 Å. In the eleventh C site, C(11) is bonded in a 2-coordinate geometry to one C(12), one N(2), and one H(5) atom. The C(11)-C(12) bond length is 1.39 Å. The C(11)-N(2) bond length is 1.34 Å. The C(11)-H(5) 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 1.38 Å. In the thirteenth C site, C(13) is bonded in a bent 120 degrees geometry to one C(12), one O(7), and one O(8) atom. The C(13)-O(7) bond length is 1.25 Å. The C(13)-O(8) bond length is 1.25 Å. In the fourteenth C site, C(14) is bonded in a distorted single-bond geometry to one C(12), one C(9), and one H(6) atom. The C(14)-H(6) bond length is 0.93 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded in a bent 120 degrees geometry to one C(3) and one C(4) atom. In the second N site, N(2) is bonded in a trigonal planar geometry to one Mg(1), one C(10), and one C(11) atom. 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(4) 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 C(10) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(11) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one C(14) atom. There are eight 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 bent 120 degrees geometry to one Mg(2) and one C(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Mg(2) and one C(6) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Mg(2) and one C(6) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Mg(2) and one C(8) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Mg(1) and one C(8) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Mg(1) and one C(13) atom. In the eighth O site, O(8) is bonded in a water-like geometry to one Mg(2) and one C(13) atom. Linkers: 8 [O]C(=O)c1cncc(C([O])=O)c1. Metal clusters: 2 O=[C]O[Mg]O[C]=O.O=[C]O[Mg]O[C]=O.[C]1O[Mg]O[C]O[Mg]O1.[O][C]=O.[O][C]=O. RCSR code: bcu. The MOF has largest included sphere 6.58 A, density 0.94 g/cm3, surface area 4138.29 m2/g, accessible volume 0.63 cm3/g