UCuH6(C5O6)2 crystallizes in the triclinic P-1 space group. U(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. Both U(1)-O(1) bond lengths are 1.81 Å. Both U(1)-O(2) bond lengths are 2.39 Å. Both U(1)-O(3) bond lengths are 2.53 Å. Both U(1)-O(4) bond lengths are 2.57 Å. Cu(1) is bonded in a distorted octahedral geometry to two equivalent O(1), two equivalent O(5), and two equivalent O(6) atoms. Both Cu(1)-O(1) bond lengths are 2.52 Å. Both Cu(1)-O(5) bond lengths are 1.99 Å. Both Cu(1)-O(6) bond lengths are 1.96 Å. There are five inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one C(2), one O(3), and one O(4) atom. The C(1)-C(2) bond length is 1.49 Å. The C(1)-O(3) bond length is 1.29 Å. The C(1)-O(4) bond length is 1.27 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one C(1), one C(3), and one C(4) atom. The C(2)-C(3) bond length is 1.40 Å. The C(2)-C(4) bond length is 1.41 Å. In the third C site, C(3) is bonded in a distorted trigonal planar geometry to one C(2), one C(4), and one H(3) atom. The C(3)-C(4) bond length is 1.39 Å. The C(3)-H(3) bond length is 1.09 Å. In the fourth C site, C(4) is bonded in a trigonal planar geometry to one C(2), one C(3), and one C(5) atom. The C(4)-C(5) bond length is 1.50 Å. In the fifth C site, C(5) is bonded in a distorted bent 120 degrees geometry to one C(4), one O(2), and one O(6) atom. The C(5)-O(2) bond length is 1.26 Å. The C(5)-O(6) bond length is 1.27 Å. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(5) atom. The H(1)-O(5) bond length is 0.97 Å. In the second H site, H(2) is bonded in a distorted single-bond geometry to one O(3) and one O(5) atom. The H(2)-O(3) bond length is 1.68 Å. The H(2)-O(5) bond length is 1.00 Å. In the third H site, H(3) is bonded in a single-bond geometry to one C(3) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one U(1) and one Cu(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one U(1) and one C(5) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one U(1), one C(1), and one H(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one U(1) and one C(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Cu(1), one H(1), and one H(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Cu(1) and one C(5) atom. Linkers: 1 [O]C(=O)c1cc(C([O])=O)c(C([O])=O)cc1C([O])=O. Metal clusters: 1 [U] ,1 [Cu]. The MOF has largest included sphere 3.84 A, density 2.42 g/cm3, surface area 2246.52 m2/g, accessible volume 0.13 cm3/g