Cu3H4(CO)10 crystallizes in the triclinic P-1 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 two equivalent O(3) and two equivalent O(5) atoms. Both Cu(1)-O(3) bond lengths are 2.00 Å. Both Cu(1)-O(5) bond lengths are 1.96 Å. In the second Cu site, Cu(2) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(4), and two equivalent O(5) atoms. The Cu(2)-O(1) bond length is 1.97 Å. The Cu(2)-O(4) bond length is 1.95 Å. There is one shorter (1.98 Å) and one longer (2.00 Å) Cu(2)-O(5) bond length. There are five inequivalent C sites. In the first C site, C(1) is bonded in a bent 120 degrees geometry to one C(3), one O(1), and one O(2) atom. The C(1)-C(3) bond length is 1.49 Å. The C(1)-O(1) bond length is 1.29 Å. The C(1)-O(2) bond length is 1.27 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one C(4), one O(3), and one O(4) atom. The C(2)-C(4) bond length is 1.50 Å. The C(2)-O(3) bond length is 1.28 Å. The C(2)-O(4) bond length is 1.27 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one C(1), one C(4), and one C(5) atom. The C(3)-C(4) bond length is 1.41 Å. The C(3)-C(5) bond length is 1.40 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 1.39 Å. In the fifth C site, C(5) is bonded in a distorted single-bond geometry to one C(3), one C(4), and one H(1) atom. The C(5)-H(1) bond length is 1.09 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(5) atom. In the second H site, H(2) is bonded in a distorted single-bond geometry to one O(5) atom. The H(2)-O(5) bond length is 1.00 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a water-like geometry to one Cu(2) and one C(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one C(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Cu(1) and one C(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Cu(2) and one C(2) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Cu(1), two equivalent Cu(2), and one H(2) atom. Linkers: 1 [O]C(=O)c1cc(C([O])=O)c(C([O])=O)cc1C([O])=O. Metal clusters: 3 [Cu]. The MOF has largest included sphere 1.75 A, density 2.80 g/cm3, surface area 2027.11 m2/g, accessible volume 0.05 cm3/g