CoP2(HO3)2 crystallizes in the orthorhombic P2_12_12_1 space group. Co(1) is bonded to one O(1), one O(2), one O(5), and one O(6) atom to form CoO4 tetrahedra that share corners with two equivalent P(1)HO3 tetrahedra and corners with two equivalent P(2)HO3 tetrahedra. The Co(1)-O(1) bond length is 1.94 Å. The Co(1)-O(2) bond length is 1.95 Å. The Co(1)-O(5) bond length is 1.93 Å. The Co(1)-O(6) bond length is 1.96 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one H(1), one O(2), one O(3), and one O(6) atom to form distorted PHO3 tetrahedra that share corners with two equivalent Co(1)O4 tetrahedra. The P(1)-H(1) bond length is 1.43 Å. The P(1)-O(2) bond length is 1.52 Å. The P(1)-O(3) bond length is 1.52 Å. The P(1)-O(6) bond length is 1.51 Å. In the second P site, P(2) is bonded to one H(2), one O(1), one O(4), and one O(5) atom to form distorted PHO3 tetrahedra that share corners with two equivalent Co(1)O4 tetrahedra. The P(2)-H(2) bond length is 1.43 Å. The P(2)-O(1) bond length is 1.51 Å. The P(2)-O(4) bond length is 1.52 Å. The P(2)-O(5) bond length is 1.50 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 Co(1) and one P(2) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Co(1) and one P(1) atom. In the third O site, O(3) is bonded in a single-bond geometry to one P(1) atom. In the fourth O site, O(4) is bonded in a single-bond geometry to one P(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Co(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Co(1) and one P(1) atom. Linkers: 8 [O][PH]([O])=O. Metal clusters: 4 [Co]. RCSR code: cds. The MOF has largest included sphere 4.83 A, density 1.21 g/cm3, surface area 3676.77 m2/g, accessible volume 0.51 cm3/g