Cu3C6N9O crystallizes in the cubic Fd-3c space group. Cu(1) is bonded in a square co-planar geometry to one N(2), two equivalent N(1), and one O(1) atom. The Cu(1)-N(2) bond length is 2.00 Å. Both Cu(1)-N(1) bond lengths are 1.98 Å. The Cu(1)-O(1) bond length is 1.98 Å. C(1) is bonded in a water-like geometry to one N(1) and one N(2) atom. The C(1)-N(1) bond length is 1.32 Å. The C(1)-N(2) bond length is 1.35 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded in a 3-coordinate geometry to one Cu(1), one C(1), and one N(1) atom. The N(1)-N(1) bond length is 1.36 Å. In the second N site, N(2) is bonded in a trigonal planar geometry to one Cu(1) and two equivalent C(1) atoms. O(1) is bonded in a trigonal planar geometry to three equivalent Cu(1) atoms. Linkers: 35 [C]1=N[C]=N[N]1 ,36 [C]1N=[C]N=N1 ,25 [C]1=NN=[C][N]1. Metal clusters: 32 N1=N[Cu]2=NN=[Cu](N=N[Cu]1)O2. The MOF has largest included sphere 7.67 A, density 1.42 g/cm3, surface area 2792.47 m2/g, accessible volume 0.41 cm3/g