MgC8H6O5 crystallizes in the orthorhombic Pna2_1 space group. Mg(1) is bonded in a 7-coordinate geometry to one O(2), one O(4), one O(5), two equivalent O(1), and two equivalent O(3) atoms. The Mg(1)-O(2) bond length is 2.13 Å. The Mg(1)-O(4) bond length is 2.08 Å. The Mg(1)-O(5) bond length is 2.66 Å. Both Mg(1)-O(1) bond lengths are 2.13 Å. There is one shorter (2.19 Å) and one longer (2.31 Å) Mg(1)-O(3) bond length. There are eight inequivalent C sites. In the first C site, C(1) is bonded in a distorted single-bond geometry to one O(1) atom. The C(1)-O(1) bond length is 1.29 Å. In the second C site, C(2) is bonded in a distorted single-bond geometry to one C(3) and one O(2) atom. The C(2)-C(3) bond length is 1.42 Å. The C(2)-O(2) bond length is 1.26 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one C(2), one C(4), and one C(7) atom. The C(3)-C(4) bond length is 1.39 Å. The C(3)-C(7) bond length is 1.50 Å. In the fourth C site, C(4) is bonded in a distorted single-bond geometry to one C(3) and one O(3) atom. The C(4)-O(3) bond length is 1.29 Å. In the fifth C site, C(5) is bonded in a distorted single-bond geometry to one O(4) atom. The C(5)-O(4) bond length is 1.27 Å. In the sixth C site, C(6) is bonded in a distorted single-bond geometry to one O(5) atom. The C(6)-O(5) bond length is 1.38 Å. In the seventh C site, C(7) is bonded in a distorted trigonal non-coplanar geometry to one C(3), one H(1), one H(2), and one H(3) atom. The C(7)-H(1) bond length is 1.10 Å. The C(7)-H(2) bond length is 1.10 Å. The C(7)-H(3) bond length is 1.10 Å. In the eighth C site, C(8) is bonded in a tetrahedral geometry to one H(4), one H(5), one H(6), and one O(5) atom. The C(8)-H(4) bond length is 1.09 Å. The C(8)-H(5) bond length is 1.10 Å. The C(8)-H(6) bond length is 1.10 Å. The C(8)-O(5) bond length is 1.44 Å. There are six inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(7) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(7) 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(8) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(8) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one C(8) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to two equivalent 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(1) and one C(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Mg(1) and one C(4) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Mg(1) and one C(5) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Mg(1), one C(6), and one C(8) atom. Linkers: 4 COC1=C([O])C(=O)C(C)=C([O])C1=O. Metal clusters: 4 [Mg]. RCSR code: pts. The MOF has largest included sphere 1.98 A, density 1.74 g/cm3, surface area 3733.99 m2/g, accessible volume 0.09 cm3/g