Zn3P4(HO3)4 crystallizes in the monoclinic C2/c space group. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one O(1), one O(2), one O(5), and one O(6) atom to form ZnO4 tetrahedra that share corners with two equivalent P(1)HO3 tetrahedra and corners with two equivalent P(2)HO3 tetrahedra. The Zn(1)-O(1) bond length is 1.95 Å. The Zn(1)-O(2) bond length is 1.94 Å. The Zn(1)-O(5) bond length is 1.94 Å. The Zn(1)-O(6) bond length is 1.95 Å. In the second Zn site, Zn(2) is bonded to two equivalent O(3) and two equivalent O(4) atoms to form ZnO4 tetrahedra that share corners with two equivalent P(1)HO3 tetrahedra and corners with two equivalent P(2)HO3 tetrahedra. Both Zn(2)-O(3) bond lengths are 1.94 Å. Both Zn(2)-O(4) bond lengths are 1.94 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one H(1), one O(1), one O(2), and one O(3) atom to form PHO3 tetrahedra that share  a cornercorner with one Zn(2)O4 tetrahedra and corners with two equivalent Zn(1)O4 tetrahedra. The P(1)-H(1) bond length is 1.32 Å. The P(1)-O(1) bond length is 1.51 Å. The P(1)-O(2) bond length is 1.51 Å. The P(1)-O(3) bond length is 1.53 Å. In the second P site, P(2) is bonded to one H(2), one O(4), one O(5), and one O(6) atom to form distorted PHO3 tetrahedra that share  a cornercorner with one Zn(2)O4 tetrahedra and corners with two equivalent Zn(1)O4 tetrahedra. The P(2)-H(2) bond length is 1.32 Å. The P(2)-O(4) bond length is 1.53 Å. The P(2)-O(5) bond length is 1.50 Å. The P(2)-O(6) bond length is 1.52 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one P(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one P(2) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Zn(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Zn(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Zn(2) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Zn(2) and one P(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Zn(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Zn(1) and one P(2) atom. Linkers: 16 [O][PH]([O])=O. Metal clusters: 12 [Zn]. The MOF has largest included sphere 4.22 A, density 1.69 g/cm3, surface area 3203.05 m2/g, accessible volume 0.34 cm3/g