InC2HO5 crystallizes in the trigonal R3c space group. In(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(1) atoms to form corner-sharing InO6 pentagonal pyramids. The In(1)-O(2) bond length is 2.22 Å. The In(1)-O(3) bond length is 2.31 Å. The In(1)-O(4) bond length is 2.25 Å. The In(1)-O(5) bond length is 2.24 Å. There is one shorter (2.07 Å) and one longer (2.12 Å) In(1)-O(1) bond length. There are two inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one O(2) and one O(4) atom. The C(1)-O(2) bond length is 1.27 Å. The C(1)-O(4) bond length is 1.24 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one O(3) and one O(5) atom. The C(2)-O(3) bond length is 1.24 Å. The C(2)-O(5) bond length is 1.24 Å. H(1) is bonded in a single-bond geometry to one O(1) atom. The H(1)-O(1) bond length is 0.82 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to two equivalent In(1) and one H(1) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one In(1) and one C(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one In(1) and one C(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one In(1) and one C(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one In(1) and one C(2) atom. Linkers: 6 [O]C(=O)C([O])=O. Metal clusters: 6 [In]. The MOF has largest included sphere 4.22 A, density 2.74 g/cm3, surface area 1966.12 m2/g, accessible volume 0.11 cm3/g