ZnC2H2O5 crystallizes in the orthorhombic Pbca space group. Zn(1) is bonded to one O(1), one O(2), one O(4), one O(5), and two equivalent O(3) atoms to form distorted corner-sharing ZnO6 octahedra. The corner-sharing octahedral tilt angles are 49°. The Zn(1)-O(1) bond length is 2.04 Å. The Zn(1)-O(2) bond length is 2.26 Å. The Zn(1)-O(4) bond length is 2.06 Å. The Zn(1)-O(5) bond length is 2.05 Å. There is one shorter (2.11 Å) and one longer (2.35 Å) Zn(1)-O(3) bond length. There are two inequivalent C sites. In the first C site, C(2) is bonded in a distorted bent 120 degrees geometry to one O(2) and one O(4) atom. The C(2)-O(2) bond length is 1.26 Å. The C(2)-O(4) bond length is 1.27 Å. In the second C site, C(1) is bonded in a distorted bent 120 degrees geometry to one O(1) and one O(3) atom. The C(1)-O(1) bond length is 1.26 Å. The C(1)-O(3) bond length is 1.27 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(5) atom. The H(1)-O(5) bond length is 0.98 Å. In the second H site, H(2) is bonded in a distorted linear geometry to one O(2) and one O(5) atom. The H(2)-O(2) bond length is 1.65 Å. The H(2)-O(5) bond length is 1.00 Å. There are five inequivalent O sites. In the first O site, O(4) is bonded in a bent 120 degrees geometry to one Zn(1) and one C(2) atom. In the second O site, O(1) is bonded in a bent 120 degrees geometry to one Zn(1) and one C(1) atom. In the third O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Zn(1), one H(1), and one H(2) atom. In the fourth O site, O(2) is bonded in a distorted trigonal planar geometry to one Zn(1), one C(2), and one H(2) atom. In the fifth O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Zn(1) and one C(1) atom. Linkers: 8 [O]C(=O)C([O])=O. Metal clusters: 8 [Zn]. RCSR code: hcb. The MOF has largest included sphere 1.83 A, density 2.70 g/cm3, surface area 2592.40 m2/g, accessible volume 0.08 cm3/g