ZnC8N3H5O2C3N2H6O crystallizes in the monoclinic P2_1/c space group. The structure consists of four 2-imidazolidone molecules inside a ZnC8N3H5O2 framework. In the ZnC8N3H5O2 framework, Zn(1) is bonded in a tetrahedral geometry to one N(1), one N(2), one N(3), and one O(1) atom. The Zn(1)-N(1) bond length is 2.00 Å. The Zn(1)-N(2) bond length is 1.98 Å. The Zn(1)-N(3) bond length is 2.00 Å. The Zn(1)-O(1) bond length is 1.96 Å. There are eight inequivalent C sites. In the first C site, C(1) is bonded in a bent 120 degrees geometry to one C(2), one O(1), and one O(2) atom. The C(1)-C(2) bond length is 1.49 Å. The C(1)-O(1) bond length is 1.31 Å. The C(1)-O(2) bond length is 1.25 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 1.39 Å. The C(2)-C(5) bond length is 1.42 Å. In the third C site, C(3) is bonded in a distorted single-bond geometry to one C(2), one C(4), and one H(1) atom. The C(3)-C(4) bond length is 1.42 Å. The C(3)-H(1) bond length is 1.09 Å. In the fourth C site, C(4) is bonded in a trigonal planar geometry to one C(3), one C(4), and one C(8) atom. The C(4)-C(4) bond length is 1.44 Å. The C(4)-C(8) bond length is 1.42 Å. In the fifth C site, C(5) is bonded in a distorted single-bond geometry to one C(2) and one H(2) atom. The C(5)-H(2) bond length is 1.09 Å. In the sixth C site, C(6) is bonded in a trigonal planar geometry to one N(1), one N(3), and one H(3) atom. The C(6)-N(1) bond length is 1.33 Å. The C(6)-N(3) bond length is 1.35 Å. The C(6)-H(3) bond length is 1.09 Å. In the seventh C site, C(7) is bonded in a trigonal planar geometry to one N(2), one N(3), and one H(4) atom. The C(7)-N(2) bond length is 1.33 Å. The C(7)-N(3) bond length is 1.35 Å. The C(7)-H(4) bond length is 1.08 Å. In the eighth C site, C(8) is bonded in a distorted single-bond geometry to one C(4) and one H(5) atom. The C(8)-H(5) bond length is 1.09 Å. There are three inequivalent N sites. In the first N site, N(1) is bonded in a distorted trigonal planar geometry to one Zn(1), one C(6), and one N(2) atom. The N(1)-N(2) bond length is 1.37 Å. In the second N site, N(2) is bonded in a 3-coordinate geometry to one Zn(1), one C(7), and one N(1) atom. In the third N site, N(3) is bonded in a trigonal planar geometry to one Zn(1), one C(6), and one C(7) 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 C(5) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(6) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(7) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(8) atom. There are two inequivalent O sites. In the first O site, O(1) is bonded in a water-like geometry to one Zn(1) and one C(1) atom. In the second O site, O(2) is bonded in a single-bond geometry to one C(1) atom. Linkers: 2 [O]C(=O)c1ccc2cc(C([O])=O)ccc2c1 ,2 C1=NC=N[N]1 ,2 [N]1=CN=NC=1. Metal clusters: 2 O=[C]O[Zn]1=NN=[Zn](O[C]=O)N=N1. The MOF has largest included sphere 2.66 A, density 1.62 g/cm3, surface area 4582.67 m2/g, accessible volume 0.21 cm3/g