Zn3P4(HO2)8 crystallizes in the orthorhombic Fddd space group. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to four equivalent O(2) atoms to form ZnO4 tetrahedra that share corners with four equivalent P(1)O4 tetrahedra. All Zn(1)-O(2) bond lengths are 1.94 Å. In the second Zn site, Zn(2) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form ZnO4 tetrahedra that share corners with four equivalent P(1)O4 tetrahedra. Both Zn(2)-O(1) bond lengths are 1.94 Å. Both Zn(2)-O(3) bond lengths are 1.95 Å. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share  a cornercorner with one Zn(1)O4 tetrahedra and corners with two equivalent Zn(2)O4 tetrahedra. 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 1.50 Å. The P(1)-O(4) bond length is 1.61 Å. There are two inequivalent H sites. In the first H site, H(2) is bonded in a single-bond geometry to one O(4) atom. The H(2)-O(4) bond length is 0.89 Å. In the second H site, H(1) is bonded in a single-bond geometry to one O(4) atom. The H(1)-O(4) bond length is 0.90 Å. There are four inequivalent O sites. In the first O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Zn(1) and one P(1) atom. In the second O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Zn(2) and one P(1) atom. In the third O site, O(4) is bonded in a 3-coordinate geometry to one P(1), one H(1), and one H(2) atom. In the fourth O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Zn(2) and one P(1) atom. Linkers: 32 O.[O]P([O])[O]. Metal clusters: 24 [Zn]. The MOF has largest included sphere 5.18 A, density 1.69 g/cm3, surface area 2896.46 m2/g, accessible volume 0.29 cm3/g