ZnC5H5O6 crystallizes in the monoclinic P2_1/c space group. Zn(1) is bonded in a trigonal bipyramidal geometry to one O(1), one O(2), one O(3), one O(5), and one O(6) atom. The Zn(1)-O(1) bond length is 2.00 Å. The Zn(1)-O(2) bond length is 2.12 Å. The Zn(1)-O(3) bond length is 1.98 Å. The Zn(1)-O(5) bond length is 2.29 Å. The Zn(1)-O(6) bond length is 1.99 Å. There are five inequivalent C sites. In the first C site, C(3) is bonded in a trigonal planar geometry to one C(2), one C(4), and one C(5) atom. The C(3)-C(2) bond length is 1.41 Å. The C(3)-C(4) bond length is 1.50 Å. The C(3)-C(5) bond length is 1.40 Å. In the second C site, C(4) is bonded in a distorted bent 120 degrees geometry to one C(3), one O(3), and one O(4) atom. The C(4)-O(3) bond length is 1.28 Å. The C(4)-O(4) bond length is 1.27 Å. In the third C site, C(5) is bonded in a distorted single-bond geometry to one C(2), one C(3), and one H(5) atom. The C(5)-C(2) bond length is 1.40 Å. The C(5)-H(5) bond length is 1.09 Å. In the fourth C site, C(1) is bonded in a distorted bent 120 degrees geometry to one C(2), one O(1), and one O(2) atom. The C(1)-C(2) bond length is 1.50 Å. The C(1)-O(1) bond length is 1.27 Å. The C(1)-O(2) bond length is 1.27 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 O(2) and one O(5) atom. The H(1)-O(2) bond length is 1.72 Å. The H(1)-O(5) bond length is 1.00 Å. 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 0.99 Å. In the third H site, H(3) is bonded in a distorted single-bond geometry to one O(6) atom. The H(3)-O(6) bond length is 1.00 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 1.00 Å. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(5) atom. There are six inequivalent O sites. In the first O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Zn(1), one H(3), and one H(4) atom. In the second O site, O(1) is bonded in a distorted 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 water-like geometry to one Zn(1), one H(1), and one H(2) atom. In the fourth O site, O(2) is bonded in a 3-coordinate geometry to one Zn(1), one C(1), and one H(1) atom. In the fifth O site, O(3) is bonded in a bent 120 degrees geometry to one Zn(1) and one C(4) atom. In the sixth O site, O(4) is bonded in a distorted single-bond geometry to one C(4) atom. Linkers: 2 [O]C(=O)c1cc(C([O])=O)c(C([O])=O)cc1C([O])=O. Metal clusters: 4 [Zn]. The MOF has largest included sphere 2.22 A, density 2.17 g/cm3, surface area 2990.32 m2/g, accessible volume 0.09 cm3/g