MnCPHO5 crystallizes in the monoclinic P2_1/c space group. Mn(1) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(5) atom to form MnO5 square pyramids that share corners with three equivalent P(1)HO3 tetrahedra. The Mn(1)-O(1) bond length is 2.13 Å. The Mn(1)-O(2) bond length is 2.14 Å. The Mn(1)-O(3) bond length is 2.19 Å. The Mn(1)-O(4) bond length is 2.22 Å. The Mn(1)-O(5) bond length is 2.25 Å. C(1) is bonded in a distorted bent 120 degrees geometry to one O(4) and one O(5) atom. The C(1)-O(4) bond length is 1.26 Å. The C(1)-O(5) bond length is 1.26 Å. P(1) is bonded to one H(1), one O(1), one O(2), and one O(3) atom to form distorted PHO3 tetrahedra that share corners with three equivalent Mn(1)O5 square pyramids. The P(1)-H(1) bond length is 1.44 Å. The P(1)-O(1) bond length is 1.52 Å. The P(1)-O(2) bond length is 1.52 Å. The P(1)-O(3) bond length is 1.53 Å. H(1) is bonded in a single-bond geometry to one P(1) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Mn(1) and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Mn(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Mn(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Mn(1) and one C(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Mn(1) and one C(1) atom. Linkers: 1 [O]C(=O)C([O])=O. Metal clusters: 4 [Mn]. The MOF has largest included sphere 5.27 A, density 1.45 g/cm3, surface area 3518.20 m2/g, accessible volume 0.39 cm3/g