UC2PH3O7 crystallizes in the monoclinic P2_1/c space group. U(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), two equivalent O(4), and two equivalent O(5) atoms. The U(1)-O(1) bond length is 1.80 Å. The U(1)-O(2) bond length is 1.80 Å. The U(1)-O(3) bond length is 2.27 Å. There is one shorter (2.39 Å) and one longer (2.56 Å) U(1)-O(4) bond length. There is one shorter (2.38 Å) and one longer (2.51 Å) U(1)-O(5) bond length. There are two inequivalent C sites. In the first C site, C(1) is bonded in a distorted tetrahedral geometry to one C(2), one P(1), one H(2), and one H(3) atom. The C(1)-C(2) bond length is 1.50 Å. The C(1)-P(1) bond length is 1.81 Å. The C(1)-H(2) bond length is 1.10 Å. The C(1)-H(3) bond length is 1.10 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one C(1), one O(6), and one O(7) atom. The C(2)-O(6) bond length is 1.25 Å. The C(2)-O(7) bond length is 1.31 Å. P(1) is bonded in a tetrahedral geometry to one C(1), one O(3), one O(4), and one O(5) atom. The P(1)-O(3) bond length is 1.52 Å. The P(1)-O(4) bond length is 1.56 Å. The P(1)-O(5) bond length is 1.56 Å. There are three inequivalent H sites. In the first H site, H(1) is bonded in a linear geometry to one O(6) and one O(7) atom. The H(1)-O(6) bond length is 1.54 Å. The H(1)-O(7) bond length is 1.03 Å. In the second H site, H(2) is bonded in a single-bond geometry to one C(1) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(1) atom. There are seven inequivalent O sites. In the first O site, O(2) is bonded in a single-bond geometry to one U(1) atom. In the second O site, O(3) is bonded in a bent 150 degrees geometry to one U(1) and one P(1) atom. In the third O site, O(4) is bonded in a distorted single-bond geometry to two equivalent U(1) and one P(1) atom. In the fourth O site, O(5) is bonded in a distorted single-bond geometry to two equivalent U(1) and one P(1) atom. In the fifth O site, O(6) is bonded in a bent 120 degrees geometry to one C(2) and one H(1) atom. In the sixth O site, O(7) is bonded in a water-like geometry to one C(2) and one H(1) atom. In the seventh O site, O(1) is bonded in a single-bond geometry to one U(1) atom. Linkers: 4 [O]P([O])(=O)CC(=O)O. Metal clusters: 4 [U]. The MOF has largest included sphere 1.92 A, density 4.09 g/cm3, surface area 1650.04 m2/g, accessible volume 0.03 cm3/g