CsC7NH8O6 crystallizes in the monoclinic P2_1/c space group. Cs(1) is bonded in a 12-coordinate geometry to one H(5), two equivalent H(7), one O(1), one O(3), one O(4), one O(6), two equivalent O(5), and three equivalent O(2) atoms. The Cs(1)-H(5) bond length is 3.40 Å. There is one shorter (3.16 Å) and one longer (3.19 Å) Cs(1)-H(7) bond length. The Cs(1)-O(1) bond length is 3.13 Å. The Cs(1)-O(3) bond length is 3.29 Å. The Cs(1)-O(4) bond length is 3.47 Å. The Cs(1)-O(6) bond length is 3.29 Å. There is one shorter (3.28 Å) and one longer (3.35 Å) Cs(1)-O(5) bond length. There is one shorter (3.04 Å) and two longer (3.19 Å) Cs(1)-O(2) bond lengths. 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 1.40 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 H(1) atom. The C(2)-C(3) bond length is 1.39 Å. The C(2)-H(1) bond length is 1.09 Å. In the third C site, C(3) is bonded in a distorted trigonal planar geometry to one C(2), one C(4), and one H(2) atom. The C(3)-C(4) bond length is 1.40 Å. The C(3)-H(2) 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(1) atom. The C(4)-C(5) bond length is 1.40 Å. The C(4)-N(1) 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(3) atom. The C(5)-C(6) bond length is 1.39 Å. The C(5)-H(3) bond length is 1.09 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(4) atom. The C(6)-H(4) 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(3), and one O(4) atom. The C(7)-O(3) bond length is 1.28 Å. The C(7)-O(4) bond length is 1.27 Å. N(1) is bonded in a trigonal planar geometry to one C(4), one O(5), and one O(6) atom. The N(1)-O(5) bond length is 1.24 Å. The N(1)-O(6) bond length is 1.24 Å. There are eight inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(2) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(3) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(5) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(6) atom. In the fifth H site, H(5) is bonded in a distorted single-bond geometry to one Cs(1), one O(1), and one O(4) atom. The H(5)-O(1) bond length is 1.00 Å. The H(5)-O(4) bond length is 1.66 Å. In the sixth H site, H(6) is bonded in a single-bond geometry to one O(1) atom. The H(6)-O(1) bond length is 0.99 Å. In the seventh H site, H(7) is bonded in a distorted single-bond geometry to two equivalent Cs(1) and one O(2) atom. The H(7)-O(2) bond length is 1.00 Å. In the eighth H site, H(8) is bonded in a single-bond geometry to one O(2) atom. The H(8)-O(2) bond length is 0.99 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted water-like geometry to one Cs(1), one H(5), and one H(6) atom. In the second O site, O(2) is bonded in a water-like geometry to three equivalent Cs(1), one H(7), and one H(8) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Cs(1) and one C(7) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Cs(1), one C(7), and one H(5) atom. In the fifth O site, O(5) is bonded in a single-bond geometry to two equivalent Cs(1) and one N(1) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one Cs(1) and one N(1) atom. Linkers: 4 [O]C(=O)c1ccc([N+](=O)[O-])cc1. Metal clusters: 4 [Cs]. RCSR code: fes. The MOF has largest included sphere 1.57 A, density 2.15 g/cm3, surface area 3799.24 m2/g, accessible volume 0.07 cm3/g