Na2CuH10(C5O6)2 crystallizes in the monoclinic C2/c space group. Na(1) is bonded to one O(1), one O(4), one O(5), one O(6), and two equivalent O(3) atoms to form edge-sharing NaO6 octahedra. The Na(1)-O(1) bond length is 2.41 Å. The Na(1)-O(4) bond length is 2.46 Å. The Na(1)-O(5) bond length is 2.39 Å. The Na(1)-O(6) bond length is 2.40 Å. There is one shorter (2.42 Å) and one longer (2.45 Å) Na(1)-O(3) bond length. Cu(1) is bonded in a square co-planar geometry to two equivalent O(2) and two equivalent O(4) atoms. Both Cu(1)-O(2) bond lengths are 1.97 Å. Both Cu(1)-O(4) bond lengths are 1.99 Å. There are five inequivalent C sites. In the first C site, C(4) is bonded in a distorted bent 120 degrees geometry to one C(1), one O(1), and one O(2) atom. The C(4)-C(1) bond length is 1.50 Å. The C(4)-O(1) bond length is 1.25 Å. The C(4)-O(2) bond length is 1.30 Å. In the second C site, C(5) is bonded in a distorted bent 120 degrees geometry to one C(2), one O(3), and one O(4) atom. The C(5)-C(2) bond length is 1.50 Å. The C(5)-O(3) bond length is 1.26 Å. The C(5)-O(4) bond length is 1.29 Å. In the third C site, C(3) is bonded in a distorted single-bond geometry to one C(1), one C(2), and one H(1) atom. The C(3)-C(1) bond length is 1.40 Å. The C(3)-C(2) bond length is 1.40 Å. The C(3)-H(1) bond length is 1.09 Å. In the fourth C site, C(1) is bonded in a trigonal planar geometry to one C(2), one C(3), and one C(4) atom. The C(1)-C(2) bond length is 1.40 Å. In the fifth C site, C(2) is bonded in a trigonal planar geometry to one C(1), one C(3), and one C(5) atom. There are five 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 O(5) atom. The H(2)-O(5) bond length is 0.98 Å. In the third H site, H(3) is bonded in a single-bond geometry to one O(5) atom. The H(3)-O(5) bond length is 0.99 Å. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(6) atom. The H(4)-O(6) bond length is 0.98 Å. In the fifth H site, H(5) is bonded in a single-bond geometry to one O(6) atom. The H(5)-O(6) bond length is 0.99 Å. There are six 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(4) atom. In the second O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Na(1) and one C(5) atom. In the third O site, O(4) is bonded in a 3-coordinate geometry to one Na(1), one Cu(1), and one C(5) atom. In the fourth O site, O(5) is bonded in a distorted water-like geometry to one Na(1), one H(2), and one H(3) atom. In the fifth O site, O(1) is bonded in a 1-coordinate geometry to one Na(1) and one C(4) atom. In the sixth O site, O(6) is bonded in a distorted water-like geometry to one Na(1), one H(4), and one H(5) atom. Linkers: 2 [O]C(=O)c1cc(C([O])=O)c(C([O])=O)cc1C([O])=O. Metal clusters: 4 [Na] ,2 [Cu]. The MOF has largest included sphere 2.44 A, density 1.96 g/cm3, surface area 2663.97 m2/g, accessible volume 0.08 cm3/g