MgH22(C5O)2 is Indium-like structured and crystallizes in the monoclinic C2/c space group. The structure is zero-dimensional and consists of four MgH22(C5O)2 clusters. Mg(1) is bonded in a tetrahedral geometry to two equivalent C(1) and two equivalent O(1) atoms. Both Mg(1)-C(1) bond lengths are 2.16 Å. Both Mg(1)-O(1) bond lengths are 2.10 Å. There are five inequivalent C sites. In the first C site, C(2) is bonded in a distorted trigonal non-coplanar geometry to one C(1), one H(2), one H(3), and one H(4) atom. The C(2)-C(1) bond length is 1.53 Å. The C(2)-H(2) bond length is 1.10 Å. The C(2)-H(3) bond length is 1.10 Å. The C(2)-H(4) bond length is 1.11 Å. In the second C site, C(3) is bonded in a distorted trigonal non-coplanar geometry to one C(1), one H(5), one H(6), and one H(7) atom. The C(3)-C(1) bond length is 1.53 Å. The C(3)-H(5) bond length is 1.10 Å. The C(3)-H(6) bond length is 1.11 Å. The C(3)-H(7) bond length is 1.11 Å. In the third C site, C(4) is bonded in a distorted trigonal non-coplanar geometry to one H(8), one H(9), and one O(1) atom. The C(4)-H(8) bond length is 1.10 Å. The C(4)-H(9) bond length is 1.10 Å. The C(4)-O(1) bond length is 1.45 Å. In the fourth C site, C(5) is bonded in a distorted trigonal non-coplanar geometry to one H(10), one H(11), and one O(1) atom. The C(5)-H(10) bond length is 1.10 Å. The C(5)-H(11) bond length is 1.10 Å. The C(5)-O(1) bond length is 1.45 Å. In the fifth C site, C(1) is bonded to one Mg(1), one C(2), one C(3), and one H(1) atom to form distorted corner-sharing CMgHC2 tetrahedra. The C(1)-H(1) bond length is 1.11 Å. There are eleven inequivalent H sites. In the first H site, H(8) is bonded in a single-bond geometry to one C(4) atom. In the second H site, H(1) is bonded in a single-bond geometry to one C(1) atom. In the third H site, H(9) is bonded in a single-bond geometry to one C(4) atom. In the fourth H site, H(2) is bonded in a single-bond geometry to one C(2) atom. In the fifth H site, H(10) is bonded in a single-bond geometry to one C(5) atom. In the sixth H site, H(3) is bonded in a single-bond geometry to one C(2) atom. In the seventh H site, H(11) is bonded in a single-bond geometry to one C(5) atom. In the eighth H site, H(4) is bonded in a single-bond geometry to one C(2) atom. In the ninth H site, H(5) is bonded in a single-bond geometry to one C(3) atom. In the tenth H site, H(6) is bonded in a single-bond geometry to one C(3) atom. In the eleventh H site, H(7) is bonded in a single-bond geometry to one C(3) atom. O(1) is bonded in a trigonal planar geometry to one Mg(1), one C(4), and one C(5) atom. Linkers: 2 C1COCCO1. Metal clusters: 2 [Mg]. The MOF has largest included sphere 1.80 A, density 1.13 g/cm3, surface area 7091.61 m2/g, accessible volume 0.27 cm3/g