In4P7(HO3)7 crystallizes in the trigonal P-3 space group. There are three inequivalent In sites. In the first In site, In(1) is bonded to one O(2), one O(3), one O(4), one O(5), and one O(7) atom to form InO5 square pyramids that share  a cornercorner with one P(2)HO3 tetrahedra,  a cornercorner with one P(3)HO3 tetrahedra, and corners with three equivalent P(1)HO3 tetrahedra. The In(1)-O(2) bond length is 2.09 Å. The In(1)-O(3) bond length is 2.11 Å. The In(1)-O(4) bond length is 2.11 Å. The In(1)-O(5) bond length is 2.11 Å. The In(1)-O(7) bond length is 2.12 Å. In the second In site, In(2) is bonded to six equivalent O(1) atoms to form InO6 octahedra that share corners with six equivalent P(2)HO3 tetrahedra. All In(2)-O(1) bond lengths are 2.12 Å. In the third In site, In(3) is bonded to six equivalent O(6) atoms to form InO6 octahedra that share corners with six equivalent P(2)HO3 tetrahedra. All In(3)-O(6) bond lengths are 2.14 Å. There are three inequivalent P sites. In the first P site, P(1) is bonded to one H(1), one O(2), one O(3), and one O(4) atom to form distorted PHO3 tetrahedra that share corners with three equivalent In(1)O5 square pyramids. The P(1)-H(1) bond length is 1.37 Å. The P(1)-O(2) bond length is 1.50 Å. The P(1)-O(3) bond length is 1.52 Å. The P(1)-O(4) bond length is 1.52 Å. In the second P site, P(2) is bonded to one H(2), one O(1), one O(6), and one O(7) atom to form distorted PHO3 tetrahedra that share  a cornercorner with one In(2)O6 octahedra,  a cornercorner with one In(3)O6 octahedra, and  a cornercorner with one In(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 42-45°. The P(2)-H(2) bond length is 1.40 Å. The P(2)-O(1) bond length is 1.52 Å. The P(2)-O(6) bond length is 1.52 Å. The P(2)-O(7) bond length is 1.51 Å. In the third P site, P(3) is bonded to one H(3) and three equivalent O(5) atoms to form distorted PHO3 tetrahedra that share corners with three equivalent In(1)O5 square pyramids. The P(3)-H(3) bond length is 1.38 Å. All P(3)-O(5) bond lengths are 1.50 Å. There are three inequivalent H sites. In the first H site, H(3) is bonded in a single-bond geometry to one P(3) atom. In the second H site, H(1) is bonded in a single-bond geometry to one P(1) atom. In the third H site, H(2) is bonded in a single-bond geometry to one P(2) atom. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one In(2) and one P(2) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one In(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one In(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one In(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one In(1) and one P(3) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one In(3) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one In(1) and one P(2) atom. Linkers: 14 [O][PH]([O])=O. Metal clusters: 8 [In]. The MOF has largest included sphere 4.51 A, density 2.20 g/cm3, surface area 2373.64 m2/g, accessible volume 0.18 cm3/g