CuC5H4O4 crystallizes in the orthorhombic C222_1 space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a rectangular see-saw-like geometry to two equivalent O(2) and two equivalent O(3) atoms. Both Cu(1)-O(2) bond lengths are 1.98 Å. Both Cu(1)-O(3) bond lengths are 1.94 Å. In the second Cu site, Cu(2) is bonded in a rectangular see-saw-like geometry to two equivalent O(1) and two equivalent O(4) atoms. Both Cu(2)-O(1) bond lengths are 1.98 Å. Both Cu(2)-O(4) bond lengths are 1.94 Å. There are six inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one C(5), one O(1), and one O(3) atom. The C(1)-C(5) bond length is 1.49 Å. The C(1)-O(1) bond length is 1.27 Å. The C(1)-O(3) bond length is 1.28 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one C(6), one O(2), and one O(4) atom. The C(2)-C(6) bond length is 1.49 Å. The C(2)-O(2) bond length is 1.27 Å. The C(2)-O(4) bond length is 1.28 Å. In the third C site, C(3) is bonded in a distorted bent 120 degrees geometry to one C(5), one H(1), and one H(3) atom. The C(3)-C(5) bond length is 1.54 Å. The C(3)-H(1) bond length is 1.09 Å. The C(3)-H(3) bond length is 1.09 Å. In the fourth C site, C(4) is bonded in a distorted bent 120 degrees geometry to one C(6), one H(2), and one H(4) atom. The C(4)-C(6) bond length is 1.54 Å. The C(4)-H(2) bond length is 1.09 Å. The C(4)-H(4) bond length is 1.09 Å. In the fifth C site, C(5) is bonded in a distorted tetrahedral geometry to two equivalent C(1) and two equivalent C(3) atoms. In the sixth C site, C(6) is bonded in a distorted tetrahedral geometry to two equivalent C(2) and two equivalent C(4) atoms. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(3) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(4) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(3) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(4) atom. There are four inequivalent O sites. In the first O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Cu(2) and one C(2) atom. In the second O site, O(1) is bonded in a water-like geometry to one Cu(2) and one C(1) atom. In the third O site, O(2) is bonded in a water-like geometry to one Cu(1) and one C(2) atom. In the fourth O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Cu(1) and one C(1) atom. Linkers: 4 [O]C(=O)C1(C([O])=O)CC1. Metal clusters: 4 [Cu]. RCSR code: ths. The MOF has largest included sphere 1.47 A, density 2.28 g/cm3, surface area 3550.17 m2/g, accessible volume 0.07 cm3/g