Zn7(PO4)6 crystallizes in the trigonal R-3 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(3), and one O(4) atom to form ZnO4 tetrahedra that share  a cornercorner with one Zn(2)O6 octahedra and corners with four equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 68°. The Zn(1)-O(1) bond length is 1.89 Å. The Zn(1)-O(2) bond length is 1.91 Å. The Zn(1)-O(3) bond length is 1.96 Å. The Zn(1)-O(4) bond length is 2.00 Å. In the second Zn site, Zn(2) is bonded to six equivalent O(4) atoms to form ZnO6 octahedra that share corners with six equivalent Zn(1)O4 tetrahedra and corners with six equivalent P(1)O4 tetrahedra. All Zn(2)-O(4) bond lengths are 2.14 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(2)O6 octahedra and corners with four equivalent Zn(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 49°. The P(1)-O(1) bond length is 1.51 Å. The P(1)-O(2) bond length is 1.53 Å. The P(1)-O(3) bond length is 1.52 Å. The P(1)-O(4) bond length is 1.55 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Zn(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Zn(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Zn(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Zn(1), one Zn(2), and one P(1) atom. Linkers: 18 [O]P([O])([O])=O. Metal clusters: 21 [Zn]. The MOF has largest included sphere 6.68 A, density 2.09 g/cm3, surface area 2156.37 m2/g, accessible volume 0.25 cm3/g