CoH6(C4N5)2 crystallizes in the monoclinic C2/c space group. Co(1) is bonded in an octahedral geometry to two equivalent N(1), two equivalent N(2), and two equivalent N(4) atoms. Both Co(1)-N(1) bond lengths are 1.98 Å. Both Co(1)-N(2) bond lengths are 2.34 Å. Both Co(1)-N(4) bond lengths are 1.94 Å. There are four inequivalent C sites. In the first C site, C(2) is bonded in a trigonal planar geometry to one C(1), one C(2), and one C(3) atom. The C(2)-C(1) bond length is 1.39 Å. The C(2)-C(2) bond length is 1.47 Å. The C(2)-C(3) bond length is 1.39 Å. In the second C site, C(3) is bonded in a distorted trigonal planar geometry to one C(2), one N(2), and one H(2) atom. The C(3)-N(2) bond length is 1.34 Å. The C(3)-H(2) bond length is 1.08 Å. In the third C site, C(4) is bonded in a trigonal planar geometry to one N(1), one N(2), and one H(3) atom. The C(4)-N(1) bond length is 1.36 Å. The C(4)-N(2) bond length is 1.34 Å. The C(4)-H(3) 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 N(1), and one H(1) atom. The C(1)-N(1) bond length is 1.35 Å. The C(1)-H(1) bond length is 1.09 Å. There are five inequivalent N sites. In the first N site, N(2) is bonded in a distorted trigonal planar geometry to one Co(1), one C(3), and one C(4) atom. In the second N site, N(3) is bonded in a linear geometry to one N(4) and one N(5) atom. The N(3)-N(4) bond length is 1.20 Å. The N(3)-N(5) bond length is 1.17 Å. In the third N site, N(4) is bonded in a distorted bent 120 degrees geometry to one Co(1) and one N(3) atom. In the fourth N site, N(5) is bonded in a single-bond geometry to one N(3) atom. In the fifth N site, N(1) is bonded in a trigonal planar geometry to one Co(1), one C(1), and one C(4) atom. There are three 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(3) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(4) atom. Linkers: 2 c1ncc(-c2cncnc2)cn1. Metal clusters: 2 [Co]. The MOF has largest included sphere 2.15 A, density 1.98 g/cm3, surface area 3008.39 m2/g, accessible volume 0.06 cm3/g