Co3P4(HO3)4 crystallizes in the monoclinic C2/c space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(2), one O(3), one O(4), 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(2) bond length is 1.96 Å. The Co(1)-O(3) bond length is 1.94 Å. The Co(1)-O(4) bond length is 1.97 Å. The Co(1)-O(6) bond length is 1.95 Å. In the second Co site, Co(2) is bonded to two equivalent O(1) and two equivalent O(5) atoms to form distorted CoO4 tetrahedra that share corners with two equivalent P(1)HO3 tetrahedra and corners with two equivalent P(2)HO3 tetrahedra. Both Co(2)-O(1) bond lengths are 1.95 Å. Both Co(2)-O(5) bond lengths are 1.94 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one H(1), one O(1), one O(2), and one O(3) atom to form PHO3 tetrahedra that share  a cornercorner with one Co(2)O4 tetrahedra and corners with two equivalent Co(1)O4 tetrahedra. The P(1)-H(1) bond length is 1.27 Å. The P(1)-O(1) bond length is 1.51 Å. The P(1)-O(2) bond length is 1.49 Å. The P(1)-O(3) bond length is 1.50 Å. In the second P site, P(2) is bonded to one H(2), one O(4), one O(5), and one O(6) atom to form PHO3 tetrahedra that share  a cornercorner with one Co(2)O4 tetrahedra and corners with two equivalent Co(1)O4 tetrahedra. The P(2)-H(2) bond length is 1.32 Å. The P(2)-O(4) bond length is 1.52 Å. The P(2)-O(5) bond length is 1.51 Å. The P(2)-O(6) bond length is 1.51 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(2) and one P(1) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Co(1) and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Co(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Co(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Co(2) and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Co(1) and one P(2) atom. Linkers: 16 [O][PH]([O])=O. Metal clusters: 12 [Co]. The MOF has largest included sphere 4.44 A, density 1.65 g/cm3, surface area 2856.60 m2/g, accessible volume 0.33 cm3/g