CuC5PH5O4 crystallizes in the monoclinic P2_1/c space group. Cu(1) is bonded to one O(1), one O(3), one O(4), and two equivalent O(2) atoms to form distorted CuO5 square pyramids that share corners with four equivalent P(1)CO3 tetrahedra and  an edgeedge with one Cu(1)O5 square pyramid. The Cu(1)-O(1) bond length is 1.95 Å. The Cu(1)-O(3) bond length is 1.97 Å. The Cu(1)-O(4) bond length is 2.00 Å. There is one shorter (1.97 Å) and one longer (2.52 Å) Cu(1)-O(2) bond length. There are five inequivalent C sites. In the first C site, C(2) is bonded in a trigonal planar geometry to one C(1), one C(3), and one P(1) atom. The C(2)-C(1) bond length is 1.39 Å. The C(2)-C(3) bond length is 1.42 Å. The C(2)-P(1) bond length is 1.80 Å. In the second C site, C(3) is bonded in a distorted trigonal planar geometry to one C(2), one C(4), and one H(2) atom. The C(3)-C(4) bond length is 1.38 Å. The C(3)-H(2) bond length is 1.09 Å. In the third C site, C(4) is bonded in a distorted trigonal planar geometry to one C(3), one C(5), and one H(3) atom. The C(4)-C(5) bond length is 1.42 Å. The C(4)-H(3) bond length is 1.09 Å. In the fourth C site, C(5) is bonded in a trigonal planar geometry to one C(1), one C(4), and one C(5) atom. The C(5)-C(1) bond length is 1.42 Å. The C(5)-C(5) bond length is 1.43 Å. In the fifth C site, C(1) is bonded in a distorted trigonal planar geometry to one C(2), one C(5), and one H(1) atom. The C(1)-H(1) bond length is 1.09 Å. P(1) is bonded to one C(2), one O(1), one O(2), and one O(3) atom to form PCO3 tetrahedra that share corners with four equivalent Cu(1)O5 square pyramids. The P(1)-O(1) bond length is 1.56 Å. The P(1)-O(2) bond length is 1.54 Å. The P(1)-O(3) bond length is 1.55 Å. There are five inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(3) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(4) atom. In the fourth H site, H(4) is bonded in a linear geometry to one O(1) and one O(4) atom. The H(4)-O(1) bond length is 1.60 Å. The H(4)-O(4) bond length is 1.01 Å. In the fifth H site, H(5) is bonded in a single-bond geometry to one O(3) and one O(4) atom. The H(5)-O(3) bond length is 1.73 Å. The H(5)-O(4) bond length is 1.00 Å. There are four inequivalent O sites. In the first O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Cu(1), one H(4), and one H(5) atom. In the second O site, O(1) is bonded in a trigonal planar geometry to one Cu(1), one P(1), and one H(4) atom. In the third O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Cu(1) and one P(1) atom. In the fourth O site, O(3) is bonded in a 3-coordinate geometry to one Cu(1), one P(1), and one H(5) atom. Linkers: 2 [O]P([O])(=O)c1ccc2cc(P([O])([O])=O)ccc2c1. Metal clusters: 4 [Cu]. The MOF has largest included sphere 2.35 A, density 2.30 g/cm3, surface area 2814.09 m2/g, accessible volume 0.11 cm3/g