Zn2P3H2O9 crystallizes in the monoclinic C2/c space group. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and one O(5) atom. The Zn(1)-O(1) bond length is 2.03 Å. The Zn(1)-O(2) bond length is 1.91 Å. The Zn(1)-O(3) bond length is 1.88 Å. The Zn(1)-O(4) bond length is 1.95 Å. The Zn(1)-O(5) bond length is 1.92 Å. In the second Zn site, Zn(2) is bonded to one O(6), one O(7), one O(8), and one O(9) 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(2)-O(6) bond length is 1.93 Å. The Zn(2)-O(7) bond length is 1.95 Å. The Zn(2)-O(8) bond length is 1.92 Å. The Zn(2)-O(9) bond length is 1.94 Å. There are three inequivalent P sites. In the first P site, P(1) is bonded to one H(1), one O(5), one O(7), and one O(8) atom to form PHO3 tetrahedra that share corners with two equivalent Zn(2)O4 tetrahedra. The P(1)-H(1) bond length is 1.27 Å. The P(1)-O(5) bond length is 1.51 Å. The P(1)-O(7) bond length is 1.52 Å. The P(1)-O(8) bond length is 1.51 Å. In the second P site, P(2) is bonded to one H(2), one O(4), one O(6), and one O(9) atom to form distorted PHO3 tetrahedra that share corners with two equivalent Zn(2)O4 tetrahedra. The P(2)-H(2) bond length is 1.37 Å. The P(2)-O(4) bond length is 1.51 Å. The P(2)-O(6) bond length is 1.51 Å. The P(2)-O(9) bond length is 1.52 Å. In the third P site, P(3) is bonded in a 4-coordinate geometry to one O(1), one O(2), and two equivalent O(3) atoms. The P(3)-O(1) bond length is 1.49 Å. The P(3)-O(2) bond length is 1.62 Å. There is one shorter (1.50 Å) and one longer (1.58 Å) P(3)-O(3) bond length. 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 nine inequivalent O sites. In the first O site, O(9) is bonded in a bent 120 degrees geometry to one Zn(2) and one P(2) atom. In the second O site, O(1) is bonded in a 3-coordinate geometry to one Zn(1), one P(3), and one O(2) atom. The O(1)-O(2) bond length is 0.93 Å. In the third O site, O(2) is bonded in a 3-coordinate geometry to one Zn(1), one P(3), and one O(1) atom. In the fourth O site, O(3) is bonded in a 3-coordinate geometry to one Zn(1) and two equivalent P(3) atoms. In the fifth O site, O(4) is bonded in a bent 120 degrees geometry to one Zn(1) and one P(2) atom. In the sixth O site, O(5) is bonded in a bent 120 degrees geometry to one Zn(1) and one P(1) atom. In the seventh O site, O(6) is bonded in a bent 120 degrees geometry to one Zn(2) and one P(2) atom. In the eighth O site, O(7) is bonded in a bent 120 degrees geometry to one Zn(2) and one P(1) atom. In the ninth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Zn(2) and one P(1) atom. Linkers: 4 [O]OP1OP(O[O])O1. Metal clusters: 16 [Zn]. The MOF has largest included sphere 6.97 A, density 1.55 g/cm3, surface area 2917.09 m2/g, accessible volume 0.43 cm3/g