Al2C5H5O8 crystallizes in the monoclinic C2/m space group. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form edge-sharing AlO6 octahedra. Both Al(1)-O(1) bond lengths are 1.92 Å. Both Al(1)-O(2) bond lengths are 1.87 Å. Both Al(1)-O(3) bond lengths are 1.95 Å. In the second Al site, Al(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form edge-sharing AlO6 octahedra. Both Al(2)-O(1) bond lengths are 1.93 Å. Both Al(2)-O(2) bond lengths are 1.87 Å. Both Al(2)-O(4) bond lengths are 1.95 Å. There are three inequivalent C sites. In the first C site, C(2) is bonded in a trigonal planar geometry to one C(1), one C(2), and one C(3) atom. The C(2)-C(1) bond length is 1.49 Å. The C(2)-C(2) bond length is 1.40 Å. The C(2)-C(3) bond length is 1.40 Å. In the second C site, C(3) is bonded in a distorted single-bond geometry to two equivalent C(2) and one H(1) atom. The C(3)-H(1) bond length is 1.09 Å. In the third C site, C(1) is bonded in a distorted bent 120 degrees geometry to one C(2), one O(3), and one O(4) atom. The C(1)-O(3) bond length is 1.27 Å. The C(1)-O(4) bond length is 1.27 Å. There are three 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 O(1) atom. The H(2)-O(1) bond length is 0.97 Å. In the third H site, H(3) is bonded in a single-bond geometry to one O(2) atom. The H(3)-O(2) bond length is 0.98 Å. There are four inequivalent O sites. In the first O site, O(4) is bonded in a bent 120 degrees geometry to one Al(2) and one C(1) atom. In the second O site, O(1) is bonded in a distorted single-bond geometry to one Al(1), one Al(2), and one H(2) atom. In the third O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Al(1), one Al(2), and one H(3) atom. In the fourth O site, O(3) is bonded in a bent 120 degrees geometry to one Al(1) and one C(1) atom. Linkers: 1 [O]C(=O)c1cc(C([O])=O)c(C([O])=O)cc1C([O])=O. Metal clusters: 4 [Al]. The MOF has largest included sphere 4.46 A, density 1.55 g/cm3, surface area 2927.55 m2/g, accessible volume 0.26 cm3/g