CuC2N8H2O crystallizes in the monoclinic C2/c space group. Cu(1) is bonded to two equivalent N(2), two equivalent N(3), and two equivalent O(1) atoms to form corner-sharing CuN4O2 octahedra. The corner-sharing octahedral tilt angles are 59°. Both Cu(1)-N(2) bond lengths are 1.99 Å. Both Cu(1)-N(3) bond lengths are 2.02 Å. Both Cu(1)-O(1) bond lengths are 2.53 Å. C(1) is bonded in a distorted trigonal planar geometry to one C(1), one N(3), and one N(4) atom. The C(1)-C(1) bond length is 1.46 Å. The C(1)-N(3) bond length is 1.36 Å. The C(1)-N(4) bond length is 1.34 Å. There are four inequivalent N sites. In the first N site, N(4) is bonded in a distorted water-like geometry to one C(1) and one N(2) atom. The N(4)-N(2) bond length is 1.34 Å. In the second N site, N(1) is bonded in a water-like geometry to one N(2) and one N(3) atom. The N(1)-N(2) bond length is 1.31 Å. The N(1)-N(3) bond length is 1.33 Å. In the third N site, N(2) is bonded in a distorted trigonal planar geometry to one Cu(1), one N(1), and one N(4) atom. In the fourth N site, N(3) is bonded in a distorted trigonal planar geometry to one Cu(1), one C(1), and one N(1) atom. H(1) is bonded in a single-bond geometry to one O(1) atom. The H(1)-O(1) bond length is 0.98 Å. O(1) is bonded in a water-like geometry to two equivalent Cu(1) and two equivalent H(1) atoms. Linkers: 2 [N]1N=NN=C1C1=NN=N[N]1. Metal clusters: 2 [Cu]. The MOF has largest included sphere 1.64 A, density 2.49 g/cm3, surface area 2699.62 m2/g, accessible volume 0.05 cm3/g