KCN4HO crystallizes in the monoclinic P2_1/c space group. K(1) is bonded to two equivalent N(2), two equivalent N(3), and three equivalent O(1) atoms to form distorted edge-sharing KN4O3 pentagonal bipyramids. There is one shorter (2.90 Å) and one longer (3.03 Å) K(1)-N(2) bond length. There is one shorter (2.93 Å) and one longer (3.06 Å) K(1)-N(3) bond length. There are a spread of K(1)-O(1) bond distances ranging from 2.72-2.77 Å. C(1) is bonded in a trigonal planar geometry to one N(1), one N(4), and one O(1) atom. The C(1)-N(1) bond length is 1.37 Å. The C(1)-N(4) bond length is 1.37 Å. The C(1)-O(1) bond length is 1.27 Å. There are four inequivalent N sites. In the first N site, N(1) is bonded in a 3-coordinate geometry to one C(1), one N(2), and one H(1) atom. The N(1)-N(2) bond length is 1.35 Å. The N(1)-H(1) bond length is 1.68 Å. In the second N site, N(2) is bonded in a 4-coordinate geometry to two equivalent K(1), one N(1), and one N(3) atom. The N(2)-N(3) bond length is 1.31 Å. In the third N site, N(3) is bonded in a 4-coordinate geometry to two equivalent K(1), one N(2), and one N(4) atom. The N(3)-N(4) bond length is 1.35 Å. In the fourth N site, N(4) is bonded in a 3-coordinate geometry to one C(1), one N(3), and one H(1) atom. The N(4)-H(1) bond length is 1.07 Å. H(1) is bonded in a distorted linear geometry to one N(1) and one N(4) atom. O(1) is bonded in a distorted single-bond geometry to three equivalent K(1) and one C(1) atom. Linkers: 4 O=C1[N]N=NN1. Metal clusters: 4 [K]. The MOF has largest included sphere 1.10 A, density 1.95 g/cm3, surface area 1277.61 m2/g, accessible volume 0.04 cm3/g