AlC8O5 crystallizes in the tetragonal I4_1 space group. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(2), one O(5), one O(7), one O(8), and two equivalent O(1) atoms to form corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles are 56°. The Al(1)-O(2) bond length is 1.90 Å. The Al(1)-O(5) bond length is 1.97 Å. The Al(1)-O(7) bond length is 1.91 Å. The Al(1)-O(8) bond length is 1.91 Å. Both Al(1)-O(1) bond lengths are 1.87 Å. In the second Al site, Al(2) is bonded to one O(3), one O(4), one O(6), one O(9), and two equivalent O(10) atoms to form corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles are 54°. The Al(2)-O(3) bond length is 1.92 Å. The Al(2)-O(4) bond length is 1.92 Å. The Al(2)-O(6) bond length is 1.89 Å. The Al(2)-O(9) bond length is 1.96 Å. There is one shorter (1.91 Å) and one longer (1.92 Å) Al(2)-O(10) bond length. There are sixteen inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one C(3), one C(4), and one C(5) atom. The C(1)-C(3) bond length is 1.48 Å. The C(1)-C(4) bond length is 1.42 Å. The C(1)-C(5) bond length is 1.41 Å. In the second C site, C(2) is bonded in a bent 120 degrees geometry to one C(7) and one C(8) atom. The C(2)-C(7) bond length is 1.42 Å. The C(2)-C(8) bond length is 1.39 Å. In the third C site, C(3) is bonded in a bent 120 degrees geometry to one C(1), one O(2), and one O(5) atom. The C(3)-O(2) bond length is 1.24 Å. The C(3)-O(5) bond length is 1.28 Å. In the fourth C site, C(4) is bonded in a bent 120 degrees geometry to one C(1) and one C(8) atom. The C(4)-C(8) bond length is 1.39 Å. In the fifth C site, C(5) is bonded in a bent 120 degrees geometry to one C(1) and one C(7) atom. The C(5)-C(7) bond length is 1.41 Å. In the sixth C site, C(6) is bonded in a bent 120 degrees geometry to one C(7), one O(3), and one O(4) atom. The C(6)-C(7) bond length is 1.48 Å. The C(6)-O(3) bond length is 1.30 Å. The C(6)-O(4) bond length is 1.22 Å. In the seventh C site, C(7) is bonded in a trigonal planar geometry to one C(2), one C(5), and one C(6) atom. In the eighth C site, C(8) is bonded in a bent 120 degrees geometry to one C(2) and one C(4) atom. In the ninth C site, C(9) is bonded in a trigonal planar geometry to one C(11), one C(12), and one C(13) atom. The C(9)-C(11) bond length is 1.47 Å. The C(9)-C(12) bond length is 1.41 Å. The C(9)-C(13) bond length is 1.40 Å. In the tenth C site, C(10) is bonded in a bent 120 degrees geometry to one C(15) and one C(16) atom. The C(10)-C(15) bond length is 1.41 Å. The C(10)-C(16) bond length is 1.39 Å. In the eleventh C site, C(11) is bonded in a distorted bent 120 degrees geometry to one C(9), one O(6), and one O(9) atom. The C(11)-O(6) bond length is 1.24 Å. The C(11)-O(9) bond length is 1.23 Å. In the twelfth C site, C(12) is bonded in a bent 120 degrees geometry to one C(16) and one C(9) atom. The C(12)-C(16) bond length is 1.39 Å. In the thirteenth C site, C(13) is bonded in a bent 120 degrees geometry to one C(15) and one C(9) atom. The C(13)-C(15) bond length is 1.40 Å. In the fourteenth C site, C(14) is bonded in a distorted bent 120 degrees geometry to one C(15), one O(7), and one O(8) atom. The C(14)-C(15) bond length is 1.47 Å. The C(14)-O(7) bond length is 1.24 Å. The C(14)-O(8) bond length is 1.26 Å. In the fifteenth C site, C(15) is bonded in a trigonal planar geometry to one C(10), one C(13), and one C(14) atom. In the sixteenth C site, C(16) is bonded in a bent 120 degrees geometry to one C(10) and one C(12) atom. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to two equivalent Al(1) atoms. In the second O site, O(9) is bonded in a bent 120 degrees geometry to one Al(2) and one C(11) atom. In the third O site, O(10) is bonded in a bent 120 degrees geometry to two equivalent Al(2) atoms. In the fourth O site, O(2) is bonded in a bent 150 degrees geometry to one Al(1) and one C(3) atom. In the fifth O site, O(3) is bonded in a bent 150 degrees geometry to one Al(2) and one C(6) atom. In the sixth O site, O(4) is bonded in a bent 120 degrees geometry to one Al(2) and one C(6) atom. In the seventh O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Al(1) and one C(3) atom. In the eighth O site, O(6) is bonded in a bent 150 degrees geometry to one Al(2) and one C(11) atom. In the ninth O site, O(7) is bonded in a bent 150 degrees geometry to one Al(1) and one C(14) atom. In the tenth O site, O(8) is bonded in a bent 120 degrees geometry to one Al(1) and one C(14) atom. Linkers: 16 [O]C(=O)c1[c][c][c]c(C([O])=O)[c]1. Metal clusters: 16 [Al]. The MOF has largest included sphere 6.64 A, density 1.11 g/cm3, surface area 3854.73 m2/g, accessible volume 0.41 cm3/g