InCP2H3O9 crystallizes in the orthorhombic Cmcm space group. In(1) is bonded in a distorted hexagonal bipyramidal geometry to one O(3), one O(4), one O(5), one O(6), two equivalent O(1), and two equivalent O(2) atoms. The In(1)-O(3) bond length is 2.08 Å. The In(1)-O(4) bond length is 2.09 Å. The In(1)-O(5) bond length is 2.24 Å. The In(1)-O(6) bond length is 2.21 Å. Both In(1)-O(1) bond lengths are 2.12 Å. Both In(1)-O(2) bond lengths are 2.08 Å. C(1) is bonded in a distorted bent 120 degrees geometry to one O(5) and one O(6) atom. The C(1)-O(5) bond length is 1.24 Å. The C(1)-O(6) bond length is 1.26 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded in a 7-coordinate geometry to one H(1), one H(2), one O(3), two equivalent O(1), and two equivalent O(2) atoms. The P(1)-H(1) bond length is 1.39 Å. The P(1)-H(2) bond length is 1.39 Å. The P(1)-O(3) bond length is 1.50 Å. Both P(1)-O(1) bond lengths are 1.42 Å. Both P(1)-O(2) bond lengths are 1.47 Å. In the second P site, P(2) is bonded in a 5-coordinate geometry to one P(2), one H(3), one O(7), and two equivalent O(4) atoms. The P(2)-P(2) bond length is 1.42 Å. The P(2)-H(3) bond length is 1.44 Å. The P(2)-O(7) bond length is 1.48 Å. Both P(2)-O(4) bond lengths are 1.56 Å. There are three inequivalent H sites. In the first H site, H(3) is bonded in a single-bond geometry to one P(2) atom. In the second H site, H(1) is bonded in a 3-coordinate geometry to one P(1) and two equivalent O(2) atoms. Both H(1)-O(2) bond lengths are 1.58 Å. In the third H site, H(2) is bonded in a 3-coordinate geometry to one P(1) and two equivalent O(1) atoms. Both H(2)-O(1) bond lengths are 1.69 Å. There are seven inequivalent O sites. In the first O site, O(3) is bonded in a distorted bent 150 degrees geometry to one In(1) and one P(1) atom. In the second O site, O(4) is bonded in a 3-coordinate geometry to one In(1) and two equivalent P(2) atoms. In the third O site, O(5) is bonded in a distorted bent 120 degrees geometry to one In(1) and one C(1) atom. In the fourth O site, O(6) is bonded in a bent 120 degrees geometry to one In(1) and one C(1) atom. In the fifth O site, O(1) is bonded in a 4-coordinate geometry to one In(1), one P(1), one H(2), and one O(2) atom. The O(1)-O(2) bond length is 0.74 Å. In the sixth O site, O(7) is bonded in a distorted single-bond geometry to one P(2) and one O(7) atom. The O(7)-O(7) bond length is 0.97 Å. In the seventh O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one In(1), one P(1), one H(1), and one O(1) atom. Linkers: 4 [H].[O].[O]OPO[O] ,4 O1O[P@H]2O[P@@H]12.[O] ,4 [O]O[PH2]([O])O[O] ,4 [O]C(=O)C([O])=O. Metal clusters: 8 [In]. The MOF has largest included sphere 4.21 A, density 2.44 g/cm3, surface area 2008.58 m2/g, accessible volume 0.19 cm3/g