ZnH8(C5O2)2 crystallizes in the monoclinic C2/c space group. Zn(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form edge-sharing ZnO6 octahedra. Both Zn(1)-O(1) bond lengths are 2.01 Å. There are two shorter (2.15 Å) and two longer (2.22 Å) Zn(1)-O(2) bond lengths. There are five inequivalent C sites. In the first 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 1.41 Å. The C(1)-C(3) bond length is 1.40 Å. The C(1)-C(4) bond length is 1.49 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one C(1), one C(3), and one C(5) atom. The C(2)-C(3) bond length is 1.40 Å. The C(2)-C(5) bond length is 1.50 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)-H(1) 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 O(1), and one O(2) atom. The C(4)-O(1) bond length is 1.27 Å. The C(4)-O(2) bond length is 1.29 Å. In the fifth C site, C(5) is bonded in a distorted trigonal non-coplanar geometry to one C(2), one H(2), one H(3), and one H(4) atom. The C(5)-H(2) bond length is 1.10 Å. The C(5)-H(3) bond length is 1.10 Å. The C(5)-H(4) bond length is 1.10 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(5) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(5) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(5) atom. There are two inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Zn(1) and one C(4) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Zn(1) and one C(4) atom. Linkers: 2 [CH2]c1cc(C([O])=O)c(C)cc1[C][O] ,2 Cc1cc(C([O])=O)c(C)cc1C([O])=O. Metal clusters: 2 [Zn]. The MOF has largest included sphere 2.69 A, density 1.78 g/cm3, surface area 3531.07 m2/g, accessible volume 0.12 cm3/g