ZnC9N5H5CO2 crystallizes in the trigonal R3c space group. The structure consists of eighteen carbon dioxide molecules inside a ZnC9N5H5 framework. In the ZnC9N5H5 framework, Zn(1) is bonded in a tetrahedral geometry to one N(1), one N(2), one N(3), and one N(4) atom. The Zn(1)-N(1) bond length is 2.10 Å. The Zn(1)-N(2) bond length is 1.99 Å. The Zn(1)-N(3) bond length is 2.00 Å. The Zn(1)-N(4) bond length is 2.02 Å. There are nine inequivalent C sites. In the first C site, C(5) is bonded in a distorted trigonal planar geometry to one C(1), one N(4), and one N(5) atom. The C(5)-C(1) bond length is 1.44 Å. The C(5)-N(4) bond length is 1.38 Å. The C(5)-N(5) bond length is 1.33 Å. In the second C site, C(6) is bonded in a distorted single-bond geometry to one C(3), one C(9), and one N(5) atom. The C(6)-C(3) bond length is 1.44 Å. The C(6)-C(9) bond length is 1.39 Å. The C(6)-N(5) bond length is 1.38 Å. In the third C site, C(7) is bonded in a distorted trigonal planar geometry to one N(3) and one H(3) atom. The C(7)-N(3) bond length is 1.36 Å. The C(7)-H(3) bond length is 1.09 Å. In the fourth C site, C(8) is bonded in a distorted bent 120 degrees geometry to one C(4), one N(2), and one H(4) atom. The C(8)-C(4) bond length is 1.39 Å. The C(8)-N(2) bond length is 1.38 Å. The C(8)-H(4) bond length is 1.08 Å. In the fifth C site, C(9) is bonded in a distorted trigonal planar geometry to one C(6), one N(3), and one H(5) atom. The C(9)-N(3) bond length is 1.35 Å. The C(9)-H(5) bond length is 1.09 Å. In the sixth C site, C(1) is bonded in a distorted trigonal planar geometry to one C(5), one N(1), and one N(2) atom. The C(1)-N(1) bond length is 1.35 Å. The C(1)-N(2) bond length is 1.35 Å. In the seventh C site, C(2) is bonded in a distorted single-bond geometry to one C(3) and one H(1) atom. The C(2)-C(3) bond length is 1.40 Å. The C(2)-H(1) bond length is 1.09 Å. In the eighth C site, C(3) is bonded in a distorted single-bond geometry to one C(2), one C(6), and one N(4) atom. The C(3)-N(4) bond length is 1.37 Å. In the ninth C site, C(4) is bonded in a distorted bent 120 degrees geometry to one C(8), one N(1), and one H(2) atom. The C(4)-N(1) bond length is 1.37 Å. The C(4)-H(2) bond length is 1.08 Å. There are five inequivalent N sites. In the first N site, N(1) is bonded in a distorted trigonal non-coplanar geometry to one Zn(1), one C(1), and one C(4) atom. In the second N site, N(2) is bonded in a trigonal planar geometry to one Zn(1), one C(1), and one C(8) atom. In the third N site, N(3) is bonded in a trigonal planar geometry to one Zn(1), one C(7), and one C(9) atom. In the fourth N site, N(4) is bonded in a distorted trigonal planar geometry to one Zn(1), one C(3), and one C(5) atom. In the fifth N site, N(5) is bonded in a water-like geometry to one C(5) and one C(6) atom. There are five inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(2) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(4) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(7) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(8) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(9) atom. Linkers: 6 C1=CN=C(C2=Nc3ccncc3[N]2)[N]1. Metal clusters: 6 [Zn]. The MOF has largest included sphere 2.53 A, density 1.75 g/cm3, surface area 4417.72 m2/g, accessible volume 0.13 cm3/g