Ga4P7(HO3)7 crystallizes in the trigonal P-3c1 space group. There are three inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one O(1), one O(3), one O(4), one O(6), and one O(7) atom to form GaO5 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 Ga(1)-O(1) bond length is 1.94 Å. The Ga(1)-O(3) bond length is 1.95 Å. The Ga(1)-O(4) bond length is 1.96 Å. The Ga(1)-O(6) bond length is 1.93 Å. The Ga(1)-O(7) bond length is 1.96 Å. In the second Ga site, Ga(2) is bonded to six equivalent O(5) atoms to form GaO6 octahedra that share corners with six equivalent P(2)HO3 tetrahedra. All Ga(2)-O(5) bond lengths are 1.97 Å. In the third Ga site, Ga(3) is bonded to six equivalent O(2) atoms to form GaO6 octahedra that share corners with six equivalent P(2)HO3 tetrahedra. All Ga(3)-O(2) bond lengths are 1.97 Å. There are three inequivalent P sites. In the first P site, P(3) is bonded to one H(3) and three equivalent O(7) atoms to form distorted PHO3 tetrahedra that share corners with three equivalent Ga(1)O5 square pyramids. The P(3)-H(3) bond length is 1.31 Å. All P(3)-O(7) bond lengths are 1.55 Å. In the second P site, P(1) is bonded to one H(1), one O(1), one O(3), and one O(6) atom to form distorted PHO3 tetrahedra that share corners with three equivalent Ga(1)O5 square pyramids. The P(1)-H(1) bond length is 1.32 Å. The P(1)-O(1) bond length is 1.52 Å. The P(1)-O(3) bond length is 1.52 Å. The P(1)-O(6) bond length is 1.52 Å. In the third P site, P(2) is bonded to one H(2), one O(2), one O(4), and one O(5) atom to form distorted PHO3 tetrahedra that share  a cornercorner with one Ga(2)O6 octahedra,  a cornercorner with one Ga(3)O6 octahedra, and  a cornercorner with one Ga(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 42-49°. The P(2)-H(2) bond length is 1.31 Å. The P(2)-O(2) bond length is 1.54 Å. The P(2)-O(4) bond length is 1.52 Å. The P(2)-O(5) bond length is 1.52 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 bent 150 degrees geometry to one Ga(1) and one P(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Ga(3) and one P(2) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Ga(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Ga(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Ga(2) and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Ga(1) and one P(1) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Ga(1) and one P(3) atom. Linkers: 28 [O][PH]([O])=O. Metal clusters: 16 [Ga]. The MOF has largest included sphere 4.96 A, density 2.02 g/cm3, surface area 2557.90 m2/g, accessible volume 0.21 cm3/g