KC7N2H7O5 crystallizes in the monoclinic P2_1/c space group. K(1) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms. The K(1)-O(3) bond length is 2.84 Å. There is one shorter (2.75 Å) and one longer (2.76 Å) K(1)-O(1) bond length. There is one shorter (2.84 Å) and one longer (2.98 Å) K(1)-O(4) bond length. There is one shorter (2.71 Å) and one longer (2.83 Å) K(1)-O(5) bond length. There are seven inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one C(2), one C(6), and one C(7) atom. The C(1)-C(2) bond length is 1.44 Å. The C(1)-C(6) bond length is 1.40 Å. The C(1)-C(7) bond length is 1.51 Å. In the second C site, C(2) is bonded in a distorted trigonal planar geometry to one C(1), one C(3), and one N(1) atom. The C(2)-C(3) bond length is 1.42 Å. The C(2)-N(1) bond length is 1.35 Å. In the third C site, C(3) is bonded in a distorted single-bond geometry to one C(2), one C(4), and one H(3) atom. The C(3)-C(4) bond length is 1.39 Å. The C(3)-H(3) bond length is 1.09 Å. In the fourth C site, C(4) is bonded in a distorted trigonal planar geometry to one C(3), one C(5), and one N(2) atom. The C(4)-C(5) bond length is 1.40 Å. The C(4)-N(2) bond length is 1.46 Å. In the fifth C site, C(5) is bonded in a distorted trigonal planar geometry to one C(4), one C(6), and one H(4) atom. The C(5)-C(6) bond length is 1.39 Å. The C(5)-H(4) bond length is 1.08 Å. In the sixth C site, C(6) is bonded in a distorted single-bond geometry to one C(1), one C(5), and one H(5) atom. The C(6)-H(5) bond length is 1.09 Å. In the seventh C site, C(7) is bonded in a distorted bent 120 degrees geometry to one C(1), one O(1), and one O(2) atom. The C(7)-O(1) bond length is 1.27 Å. The C(7)-O(2) bond length is 1.28 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded in a trigonal planar geometry to one C(2), one H(1), and one H(2) atom. The N(1)-H(1) bond length is 1.02 Å. The N(1)-H(2) bond length is 1.02 Å. In the second N site, N(2) is bonded in a trigonal planar geometry to one C(4), one O(3), and one O(4) atom. The N(2)-O(3) bond length is 1.24 Å. The N(2)-O(4) bond length is 1.25 Å. There are seven inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one N(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one N(1) 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 C(5) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(6) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one O(5) atom. The H(6)-O(5) bond length is 0.99 Å. In the seventh H site, H(7) is bonded in a single-bond geometry to one O(5) atom. The H(7)-O(5) bond length is 0.99 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to two equivalent K(1) and one C(7) atom. In the second O site, O(2) is bonded in a single-bond geometry to one C(7) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one K(1) and one N(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent K(1) and one N(2) atom. In the fifth O site, O(5) is bonded in a water-like geometry to two equivalent K(1), one H(6), and one H(7) atom. Linkers: 4 Nc1cc([N+](=O)[O-])ccc1C([O])=O. Metal clusters: 4 [K]. The MOF has largest included sphere 1.51 A, density 1.74 g/cm3, surface area 3047.84 m2/g, accessible volume 0.07 cm3/g