Cu4C5N20H6O crystallizes in the orthorhombic Pnnm space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one N(2), one N(3), one N(6), one N(9), and one O(1) atom to form distorted corner-sharing CuN4O square pyramids. The Cu(1)-N(2) bond length is 2.55 Å. The Cu(1)-N(3) bond length is 2.01 Å. The Cu(1)-N(6) bond length is 2.02 Å. The Cu(1)-N(9) bond length is 2.00 Å. The Cu(1)-O(1) bond length is 1.91 Å. In the second Cu site, Cu(2) is bonded in a square pyramidal geometry to one N(1), one N(10), one N(4), one N(5), and one N(7) atom. The Cu(2)-N(1) bond length is 2.01 Å. The Cu(2)-N(10) bond length is 2.44 Å. The Cu(2)-N(4) bond length is 2.01 Å. The Cu(2)-N(5) bond length is 2.06 Å. The Cu(2)-N(7) bond length is 2.03 Å. There are three inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one N(1), one N(4), and one H(1) atom. The C(1)-N(1) bond length is 1.32 Å. The C(1)-N(4) bond length is 1.33 Å. The C(1)-H(1) bond length is 0.93 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one N(7), one N(8), and one H(2) atom. The C(2)-N(7) bond length is 1.34 Å. The C(2)-N(8) bond length is 1.33 Å. The C(2)-H(2) bond length is 0.93 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to two equivalent N(10) and one H(3) atom. Both C(3)-N(10) bond lengths are 1.32 Å. The C(3)-H(3) bond length is 0.93 Å. There are ten inequivalent N sites. In the first N site, N(1) is bonded in a distorted trigonal planar geometry to one Cu(2), one C(1), and one N(2) atom. The N(1)-N(2) bond length is 1.33 Å. In the second N site, N(2) is bonded in a trigonal planar geometry to one Cu(1), one N(1), and one N(3) atom. The N(2)-N(3) bond length is 1.30 Å. In the third N site, N(3) is bonded in a distorted trigonal planar geometry to one Cu(1), one N(2), and one N(4) atom. The N(3)-N(4) bond length is 1.34 Å. In the fourth N site, N(4) is bonded in a 3-coordinate geometry to one Cu(2), one C(1), and one N(3) atom. In the fifth N site, N(5) is bonded in a trigonal planar geometry to one Cu(2), one N(6), and one N(8) atom. The N(5)-N(6) bond length is 1.31 Å. The N(5)-N(8) bond length is 1.34 Å. In the sixth N site, N(6) is bonded in a distorted trigonal planar geometry to one Cu(1), one N(5), and one N(7) atom. The N(6)-N(7) bond length is 1.33 Å. In the seventh N site, N(7) is bonded in a distorted trigonal planar geometry to one Cu(2), one C(2), and one N(6) atom. In the eighth N site, N(8) is bonded in a water-like geometry to one C(2) and one N(5) atom. In the ninth N site, N(9) is bonded in a distorted trigonal planar geometry to one Cu(1), one N(10), and one N(9) atom. The N(9)-N(10) bond length is 1.33 Å. The N(9)-N(9) bond length is 1.33 Å. In the tenth N site, N(10) is bonded in a 3-coordinate geometry to one Cu(2), one C(3), and one N(9) atom. There are four 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(2) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(3) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(1) atom. The H(4)-O(1) bond length is 0.83 Å. O(1) is bonded in a distorted single-bond geometry to two equivalent Cu(1) and one H(4) atom. Linkers: 8 C1=NN=N[N]1 ,4 C1=N[N]N=N1. Metal clusters: 16 [Cu]. The MOF has largest included sphere 4.26 A, density 2.02 g/cm3, surface area 2747.34 m2/g, accessible volume 0.16 cm3/g