Zn3P4(HO3)4 crystallizes in the orthorhombic Fddd space group. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form ZnO4 tetrahedra that share corners with four equivalent P(1)HO3 tetrahedra. Both Zn(1)-O(1) bond lengths are 1.94 Å. Both Zn(1)-O(2) bond lengths are 1.93 Å. In the second Zn site, Zn(2) is bonded to four equivalent O(3) atoms to form ZnO4 tetrahedra that share corners with four equivalent P(1)HO3 tetrahedra. All Zn(2)-O(3) bond lengths are 1.92 Å. P(1) is bonded to one H(1), one O(1), one O(2), and one O(3) 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(1)-H(1) bond length is 1.34 Å. The P(1)-O(1) bond length is 1.49 Å. The P(1)-O(2) bond length is 1.50 Å. The P(1)-O(3) bond length is 1.50 Å. H(1) is bonded in a single-bond geometry to one P(1) atom. There are three inequivalent O sites. In the first O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Zn(2) 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(1) is bonded in a bent 150 degrees geometry to one Zn(1) and one P(1) atom. Linkers: 32 [O][PH]([O])=O. Metal clusters: 24 [Zn]. The MOF has largest included sphere 5.23 A, density 1.50 g/cm3, surface area 3184.44 m2/g, accessible volume 0.35 cm3/g