Mn2CPH2O7 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(2), one O(5), one O(7), and two equivalent O(3) atoms to form MnO6 octahedra that share corners with four equivalent P(1)O4 tetrahedra and  an edgeedge with one Mn(1)O6 octahedra. The Mn(1)-O(1) bond length is 2.18 Å. The Mn(1)-O(2) bond length is 2.12 Å. The Mn(1)-O(5) bond length is 2.23 Å. The Mn(1)-O(7) bond length is 2.25 Å. There is one shorter (2.13 Å) and one longer (2.22 Å) Mn(1)-O(3) bond length. In the second Mn site, Mn(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(7) atom. The Mn(2)-O(1) bond length is 2.13 Å. The Mn(2)-O(2) bond length is 2.10 Å. The Mn(2)-O(4) bond length is 2.12 Å. The Mn(2)-O(5) bond length is 2.21 Å. The Mn(2)-O(6) bond length is 2.21 Å. The Mn(2)-O(7) bond length is 2.60 Å. C(1) is bonded in a distorted bent 120 degrees geometry to one O(5) and one O(6) atom. The C(1)-O(5) bond length is 1.26 Å. The C(1)-O(6) bond length is 1.27 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 corners with four equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-56°. The P(1)-O(1) bond length is 1.55 Å. The P(1)-O(2) bond length is 1.57 Å. The P(1)-O(3) bond length is 1.56 Å. The P(1)-O(4) bond length is 1.54 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(7) atom. The H(1)-O(7) bond length is 0.99 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(4) and one O(7) atom. The H(2)-O(4) bond length is 1.71 Å. The H(2)-O(7) bond length is 1.00 Å. There are seven inequivalent O sites. In the first O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Mn(1) and one P(1) atom. In the second O site, O(4) is bonded in a 3-coordinate geometry to one Mn(2), one P(1), and one H(2) atom. In the third O site, O(5) is bonded in a 3-coordinate geometry to one Mn(1), one Mn(2), and one C(1) atom. In the fourth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Mn(2) and one C(1) atom. In the fifth O site, O(7) is bonded in a distorted water-like geometry to one Mn(1), one Mn(2), one H(1), and one H(2) atom. In the sixth O site, O(1) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one P(1) atom. In the seventh O site, O(2) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(2), and one P(1) atom. Linkers: 1 [O]C(=O)C([O])=O. Metal clusters: 8 [Mn]. The MOF has largest included sphere 2.72 A, density 2.95 g/cm3, surface area 1468.91 m2/g, accessible volume 0.05 cm3/g