ZnC3N3H2O2 crystallizes in the orthorhombic Pna2_1 space group. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one N(2), one N(5), one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing ZnN2O4 octahedra. The Zn(1)-N(2) bond length is 2.13 Å. The Zn(1)-N(5) bond length is 2.06 Å. The Zn(1)-O(1) bond length is 2.21 Å. The Zn(1)-O(2) bond length is 2.20 Å. The Zn(1)-O(3) bond length is 2.13 Å. The Zn(1)-O(4) bond length is 2.10 Å. In the second Zn site, Zn(2) is bonded to one N(3), one N(4), one N(6), and one O(3) atom to form corner-sharing ZnN3O trigonal pyramids. The corner-sharing octahedral tilt angles are 60°. The Zn(2)-N(3) bond length is 1.96 Å. The Zn(2)-N(4) bond length is 2.02 Å. The Zn(2)-N(6) bond length is 1.99 Å. The Zn(2)-O(3) bond length is 2.09 Å. There are six inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one N(2), one N(6), and one H(1) atom. The C(1)-N(2) bond length is 1.33 Å. The C(1)-N(6) bond length is 1.36 Å. The C(1)-H(1) bond length is 1.09 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one N(1), one N(3), and one H(2) atom. The C(2)-N(1) bond length is 1.33 Å. The C(2)-N(3) bond length is 1.37 Å. The C(2)-H(2) bond length is 1.09 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one N(3), one N(5), and one H(3) atom. The C(3)-N(3) bond length is 1.35 Å. The C(3)-N(5) bond length is 1.33 Å. The C(3)-H(3) bond length is 1.09 Å. In the fourth C site, C(4) is bonded in a distorted bent 120 degrees geometry to one O(1) and one O(4) atom. The C(4)-O(1) bond length is 1.26 Å. The C(4)-O(4) bond length is 1.27 Å. In the fifth C site, C(5) is bonded in a distorted bent 120 degrees geometry to one O(2) and one O(3) atom. The C(5)-O(2) bond length is 1.25 Å. The C(5)-O(3) bond length is 1.28 Å. In the sixth C site, C(6) is bonded in a trigonal planar geometry to one N(4), one N(6), and one H(4) atom. The C(6)-N(4) bond length is 1.33 Å. The C(6)-N(6) bond length is 1.35 Å. The C(6)-H(4) bond length is 1.08 Å. There are six inequivalent N sites. In the first N site, N(1) is bonded in a distorted water-like geometry to one C(2) and one N(5) atom. The N(1)-N(5) bond length is 1.38 Å. In the second N site, N(2) is bonded in a distorted trigonal planar geometry to one Zn(1), one C(1), and one N(4) atom. The N(2)-N(4) bond length is 1.38 Å. In the third N site, N(3) is bonded in a trigonal planar geometry to one Zn(2), one C(2), and one C(3) atom. In the fourth N site, N(4) is bonded in a distorted trigonal planar geometry to one Zn(2), one C(6), and one N(2) atom. In the fifth N site, N(5) is bonded in a distorted trigonal planar geometry to one Zn(1), one C(3), and one N(1) atom. In the sixth N site, N(6) is bonded in a trigonal planar geometry to one Zn(2), one C(1), and one C(6) atom. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(2) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(3) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(6) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted water-like geometry to one Zn(1) and one C(4) atom. In the second O site, O(2) is bonded in a water-like geometry to one Zn(1) and one C(5) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Zn(1), one Zn(2), and one C(5) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Zn(1) and one C(4) atom. Linkers: 3 C1=NC=N[N]1 ,5 [N]1=CN=NC=1 ,4 [O]C(=O)C([O])=O. Metal clusters: 8 [Zn]. The MOF has largest included sphere 2.40 A, density 2.34 g/cm3, surface area 3002.98 m2/g, accessible volume 0.05 cm3/g