K2CuC6N4H6O9 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one N(3), one O(1), one O(3), one O(4), one O(8), one O(9), and two equivalent O(2) atoms. The K(1)-N(3) bond length is 2.92 Å. The K(1)-O(1) bond length is 3.03 Å. The K(1)-O(3) bond length is 2.81 Å. The K(1)-O(4) bond length is 2.95 Å. The K(1)-O(8) bond length is 2.77 Å. The K(1)-O(9) bond length is 2.85 Å. There is one shorter (2.85 Å) and one longer (3.00 Å) K(1)-O(2) bond length. In the second K site, K(2) is bonded in a 10-coordinate geometry to one N(3), two equivalent N(4), one H(2), one O(1), one O(4), one O(5), one O(7), one O(8), and one O(9) atom. The K(2)-N(3) bond length is 3.34 Å. There is one shorter (2.95 Å) and one longer (3.08 Å) K(2)-N(4) bond length. The K(2)-H(2) bond length is 2.97 Å. The K(2)-O(1) bond length is 2.96 Å. The K(2)-O(4) bond length is 2.94 Å. The K(2)-O(5) bond length is 2.96 Å. The K(2)-O(7) bond length is 2.98 Å. The K(2)-O(8) bond length is 2.89 Å. The K(2)-O(9) bond length is 2.73 Å. Cu(1) is bonded in a square pyramidal geometry to one N(1), one N(2), one O(3), one O(4), and one O(7) atom. The Cu(1)-N(1) bond length is 2.01 Å. The Cu(1)-N(2) bond length is 1.98 Å. The Cu(1)-O(3) bond length is 1.98 Å. The Cu(1)-O(4) bond length is 2.01 Å. The Cu(1)-O(7) bond length is 2.19 Å. There are six inequivalent C sites. In the first C site, C(1) is bonded in a distorted linear geometry to one C(3) and one N(3) atom. The C(1)-C(3) bond length is 1.41 Å. The C(1)-N(3) bond length is 1.17 Å. In the second C site, C(2) is bonded in a distorted linear geometry to one C(4) and one N(4) atom. The C(2)-C(4) bond length is 1.41 Å. The C(2)-N(4) bond length is 1.17 Å. In the third C site, C(3) is bonded in a distorted trigonal planar geometry to one C(1), one C(5), and one N(1) atom. The C(3)-C(5) bond length is 1.49 Å. The C(3)-N(1) bond length is 1.33 Å. In the fourth C site, C(4) is bonded in a distorted trigonal planar geometry to one C(2), one C(6), and one N(2) atom. The C(4)-C(6) bond length is 1.48 Å. The C(4)-N(2) bond length is 1.34 Å. In the fifth C site, C(5) is bonded in a distorted bent 120 degrees geometry to one C(3), one O(3), and one O(5) atom. The C(5)-O(3) bond length is 1.29 Å. The C(5)-O(5) bond length is 1.25 Å. In the sixth C site, C(6) is bonded in a distorted bent 120 degrees geometry to one C(4), one O(4), and one O(6) atom. The C(6)-O(4) bond length is 1.29 Å. The C(6)-O(6) bond length is 1.27 Å. There are four inequivalent N sites. In the first N site, N(1) is bonded in a trigonal planar geometry to one Cu(1), one C(3), and one O(1) atom. The N(1)-O(1) bond length is 1.29 Å. In the second N site, N(2) is bonded in a trigonal planar geometry to one Cu(1), one C(4), and one O(2) atom. The N(2)-O(2) bond length is 1.26 Å. In the third N site, N(3) is bonded in a distorted single-bond geometry to one K(1), one K(2), and one C(1) atom. In the fourth N site, N(4) is bonded in a distorted single-bond geometry to two equivalent K(2) and one C(2) atom. There are six inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(7) atom. The H(1)-O(7) bond length is 0.99 Å. In the second H site, H(2) is bonded in a single-bond geometry to one K(2) and one O(7) atom. The H(2)-O(7) bond length is 0.99 Å. In the third H site, H(3) is bonded in a single-bond geometry to one O(8) atom. The H(3)-O(8) bond length is 0.98 Å. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(8) atom. The H(4)-O(8) bond length is 0.99 Å. In the fifth H site, H(5) is bonded in a single-bond geometry to one O(9) atom. The H(5)-O(9) bond length is 0.99 Å. In the sixth H site, H(6) is bonded in a single-bond geometry to one O(9) atom. The H(6)-O(9) bond length is 0.98 Å. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one K(1), one K(2), and one N(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to two equivalent K(1) and one N(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one K(1), one Cu(1), and one C(5) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one K(1), one K(2), one Cu(1), and one C(6) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one K(2) and one C(5) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one C(6) atom. In the seventh O site, O(7) is bonded in a distorted water-like geometry to one K(2), one Cu(1), one H(1), and one H(2) atom. In the eighth O site, O(8) is bonded in a water-like geometry to one K(1), one K(2), one H(3), and one H(4) atom. In the ninth O site, O(9) is bonded in a water-like geometry to one K(1), one K(2), one H(5), and one H(6) atom. Linkers: 12 O ,8 N#C/C(=N\[O])C([O])=O. Metal clusters: 8 [K] ,4 [Cu]. The MOF has largest included sphere 2.44 A, density 2.04 g/cm3, surface area 1839.80 m2/g, accessible volume 0.05 cm3/g