In3H4(C10O9)2 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent In sites. In the first In site, In(1) is bonded to one O(1), one O(2), one O(5), one O(7), one O(8), and two equivalent O(9) atoms to form InO7 pentagonal bipyramids that share corners with two equivalent In(2)O6 octahedra and  an edgeedge with one In(1)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 49-60°. The In(1)-O(1) bond length is 2.17 Å. The In(1)-O(2) bond length is 2.21 Å. The In(1)-O(5) bond length is 2.13 Å. The In(1)-O(7) bond length is 2.26 Å. The In(1)-O(8) bond length is 2.27 Å. There is one shorter (2.20 Å) and one longer (2.31 Å) In(1)-O(9) bond length. In the second In site, In(2) is bonded to two equivalent O(3), two equivalent O(6), and two equivalent O(9) atoms to form corner-sharing InO6 octahedra. Both In(2)-O(3) bond lengths are 2.09 Å. Both In(2)-O(6) bond lengths are 2.16 Å. Both In(2)-O(9) bond lengths are 2.20 Å. There are ten inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one C(2), one C(6), and one C(7) atom. The C(1)-C(2) bond length is 1.39 Å. The C(1)-C(6) bond length is 1.40 Å. The C(1)-C(7) bond length is 1.50 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one C(1), one C(3), and one C(8) atom. The C(2)-C(3) bond length is 1.40 Å. The C(2)-C(8) bond length is 1.51 Å. In the third C site, C(3) is bonded in a distorted single-bond geometry to one C(2), one C(4), and one H(1) atom. The C(3)-C(4) bond length is 1.39 Å. The C(3)-H(1) bond length is 0.95 Å. In the fourth C site, C(4) is bonded in a trigonal planar geometry to one C(3), one C(5), and one C(9) atom. The C(4)-C(5) bond length is 1.40 Å. The C(4)-C(9) bond length is 1.50 Å. In the fifth C site, C(5) is bonded in a trigonal planar geometry to one C(10), one C(4), and one C(6) atom. The C(5)-C(10) bond length is 1.48 Å. The C(5)-C(6) bond length is 1.38 Å. In the sixth C site, C(6) is bonded in a distorted single-bond geometry to one C(1), one C(5), and one H(2) atom. The C(6)-H(2) bond length is 0.95 Å. In the seventh C site, C(7) is bonded in a distorted bent 120 degrees geometry to one C(1), one O(1), and one O(2) atom. The C(7)-O(1) bond length is 1.27 Å. The C(7)-O(2) bond length is 1.25 Å. In the eighth C site, C(8) is bonded in a distorted bent 120 degrees geometry to one C(2), one O(3), and one O(4) atom. The C(8)-O(3) bond length is 1.28 Å. The C(8)-O(4) bond length is 1.25 Å. In the ninth C site, C(9) is bonded in a distorted bent 120 degrees geometry to one C(4), one O(5), and one O(6) atom. The C(9)-O(5) bond length is 1.28 Å. The C(9)-O(6) bond length is 1.25 Å. In the tenth C site, C(10) is bonded in a distorted bent 120 degrees geometry to one C(5), one O(7), and one O(8) atom. The C(10)-O(7) bond length is 1.26 Å. The C(10)-O(8) bond length is 1.27 Å. There are two 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 C(6) atom. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one In(1) and one C(7) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one In(1) and one C(7) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one In(2) and one C(8) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one C(8) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one In(1) and one C(9) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one In(2) and one C(9) atom. In the seventh O site, O(7) is bonded in a distorted L-shaped geometry to one In(1) and one C(10) atom. In the eighth O site, O(8) is bonded in a distorted L-shaped geometry to one In(1) and one C(10) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one In(2) and two equivalent In(1) atoms. Linkers: 4 [O]C(=O)c1cc(C([O])=O)c(C([O])=O)cc1C([O])=O. Metal clusters: 6 [In]. The MOF has largest included sphere 6.08 A, density 1.75 g/cm3, surface area 2310.62 m2/g, accessible volume 0.26 cm3/g