BaCuH8(C5O4)2 crystallizes in the monoclinic C2/c space group. Ba(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and four equivalent O(4) atoms. Both Ba(1)-O(1) bond lengths are 3.03 Å. Both Ba(1)-O(2) bond lengths are 2.83 Å. Both Ba(1)-O(3) bond lengths are 2.72 Å. There are two shorter (2.78 Å) and two longer (3.24 Å) Ba(1)-O(4) bond lengths. Cu(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(2) atoms. Both Cu(1)-O(1) bond lengths are 1.93 Å. Both Cu(1)-O(2) bond lengths are 1.93 Å. There are five inequivalent C sites. In the first C site, C(1) is bonded in a distorted tetrahedral geometry to one C(2), one C(3), one C(4), and one C(5) atom. The C(1)-C(2) bond length is 1.50 Å. The C(1)-C(3) bond length is 1.54 Å. The C(1)-C(4) bond length is 1.52 Å. The C(1)-C(5) bond length is 1.50 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one C(1), one O(1), and one O(3) atom. The C(2)-O(1) bond length is 1.30 Å. The C(2)-O(3) bond length is 1.25 Å. In the third C site, C(3) is bonded in a distorted bent 120 degrees geometry to one C(1), one H(1), and one H(2) atom. The C(3)-H(1) bond length is 1.09 Å. The C(3)-H(2) 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(1), one H(3), and one H(4) atom. The C(4)-H(3) 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 bent 120 degrees geometry to one C(1), one O(2), and one O(4) atom. The C(5)-O(2) bond length is 1.30 Å. The C(5)-O(4) bond length is 1.26 Å. 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(3) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(4) 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(1) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Cu(1), and one C(2) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one Cu(1), and one C(5) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Ba(1) and one C(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one C(5) atom. Linkers: 4 [O]C(=O)C1(C([O])=O)CC1. Metal clusters: 2 [Ba] ,2 [Cu]. The MOF has largest included sphere 1.54 A, density 2.56 g/cm3, surface area 2725.60 m2/g, accessible volume 0.07 cm3/g