CuH4(C5O2)2 crystallizes in the hexagonal P6_3/mcm space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a distorted square co-planar geometry to one Cu(2) and four equivalent O(2) atoms. The Cu(1)-Cu(2) bond length is 2.46 Å. All Cu(1)-O(2) bond lengths are 1.94 Å. In the second Cu site, Cu(2) is bonded in a distorted square pyramidal geometry to one Cu(1) and four equivalent O(1) atoms. All Cu(2)-O(1) bond lengths are 1.99 Å. There are seven inequivalent C sites. In the first C site, C(4) is bonded in a trigonal planar geometry to one C(5) and two equivalent C(7) atoms. The C(4)-C(5) bond length is 1.48 Å. Both C(4)-C(7) bond lengths are 1.40 Å. In the second C site, C(7) is bonded in a distorted single-bond geometry to two equivalent C(4) and one H(3) atom. The C(7)-H(3) bond length is 1.09 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one C(1), one C(2), and one C(6) atom. The C(3)-C(1) bond length is 1.40 Å. The C(3)-C(2) bond length is 1.50 Å. The C(3)-C(6) bond length is 1.40 Å. In the fourth C site, C(5) is bonded in a trigonal planar geometry to one C(4) and two equivalent C(1) atoms. Both C(5)-C(1) bond lengths are 1.40 Å. In the fifth C site, C(6) is bonded in a distorted single-bond geometry to two equivalent C(3) and one H(2) atom. The C(6)-H(2) bond length is 1.09 Å. In the sixth C site, C(2) is bonded in a distorted bent 120 degrees geometry to one C(3), one O(1), and one O(2) atom. The C(2)-O(1) bond length is 1.28 Å. The C(2)-O(2) bond length is 1.28 Å. In the seventh C site, C(1) is bonded in a distorted single-bond geometry to one C(3), one C(5), and one H(1) atom. The C(1)-H(1) bond length is 1.09 Å. There are three inequivalent H sites. In the first H site, H(2) is bonded in a single-bond geometry to one C(6) atom. In the second H site, H(1) 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(7) atom. There are two inequivalent O sites. In the first O site, O(2) is bonded in a bent 120 degrees geometry to one Cu(1) and one C(2) atom. In the second O site, O(1) is bonded in a distorted single-bond geometry to one Cu(2) and one C(2) atom. Linkers: 4 [O]C(=O)c1cc(C([O])=O)cc(-c2cc(-c3cc(C([O])=O)cc(C([O])=O)c3)cc(-c3cc(C([O])=O)cc(C([O])=O)c3)c2)c1. Metal clusters: 6 [C]1O[Cu]234O[C]O[Cu]2(O1)(O[C]O3)O[C]O4. RCSR code: stp. The MOF has largest included sphere 10.07 A, density 0.89 g/cm3, surface area 3657.11 m2/g, accessible volume 0.71 cm3/g