CsC2H2(N3O)2 crystallizes in the orthorhombic Pca2_1 space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 9-coordinate geometry to one N(1), one N(10), one N(11), one N(2), one O(1), one O(3), one O(4), and two equivalent O(2) atoms. The Cs(1)-N(1) bond length is 3.38 Å. The Cs(1)-N(10) bond length is 3.40 Å. The Cs(1)-N(11) bond length is 3.23 Å. The Cs(1)-N(2) bond length is 3.27 Å. The Cs(1)-O(1) bond length is 3.31 Å. The Cs(1)-O(3) bond length is 3.26 Å. The Cs(1)-O(4) bond length is 3.15 Å. There is one shorter (3.09 Å) and one longer (3.21 Å) Cs(1)-O(2) bond length. In the second Cs site, Cs(2) is bonded in a 9-coordinate geometry to one N(4), one N(5), one N(7), one N(8), one O(1), one O(2), one O(3), and two equivalent O(4) atoms. The Cs(2)-N(4) bond length is 3.32 Å. The Cs(2)-N(5) bond length is 3.20 Å. The Cs(2)-N(7) bond length is 3.31 Å. The Cs(2)-N(8) bond length is 3.30 Å. The Cs(2)-O(1) bond length is 3.34 Å. The Cs(2)-O(2) bond length is 3.14 Å. The Cs(2)-O(3) bond length is 3.21 Å. There is one shorter (3.14 Å) and one longer (3.16 Å) Cs(2)-O(4) bond length. There are four inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one N(1), one N(3), and one N(4) atom. The C(1)-N(1) bond length is 1.33 Å. The C(1)-N(3) bond length is 1.37 Å. The C(1)-N(4) bond length is 1.35 Å. In the second C site, C(2) is bonded in a distorted trigonal planar geometry to one C(3), one N(2), and one N(3) atom. The C(2)-C(3) bond length is 1.44 Å. The C(2)-N(2) bond length is 1.32 Å. The C(2)-N(3) bond length is 1.39 Å. In the third C site, C(3) is bonded in a distorted trigonal planar geometry to one C(2), one N(7), and one N(9) atom. The C(3)-N(7) bond length is 1.32 Å. The C(3)-N(9) bond length is 1.39 Å. In the fourth C site, C(4) is bonded in a trigonal planar geometry to one N(10), one N(8), and one N(9) atom. The C(4)-N(10) bond length is 1.35 Å. The C(4)-N(8) bond length is 1.34 Å. The C(4)-N(9) bond length is 1.37 Å. There are twelve inequivalent N sites. In the first N site, N(1) is bonded in a distorted single-bond geometry to one Cs(1) and one C(1) atom. In the second N site, N(2) is bonded in a distorted single-bond geometry to one Cs(1) and one C(2) atom. In the third N site, N(3) is bonded in a distorted water-like geometry to one C(1), one C(2), and one N(5) atom. The N(3)-N(5) bond length is 1.39 Å. In the fourth N site, N(4) is bonded in a distorted trigonal planar geometry to one Cs(2), one C(1), one H(1), and one H(2) atom. The N(4)-H(1) bond length is 1.02 Å. The N(4)-H(2) bond length is 1.04 Å. In the fifth N site, N(5) is bonded in a 3-coordinate geometry to one Cs(2), one N(3), and one N(6) atom. The N(5)-N(6) bond length is 1.34 Å. In the sixth N site, N(6) is bonded in a trigonal planar geometry to one N(5), one O(1), and one O(2) atom. The N(6)-O(1) bond length is 1.27 Å. The N(6)-O(2) bond length is 1.27 Å. In the seventh N site, N(7) is bonded in a distorted single-bond geometry to one Cs(2) and one C(3) atom. In the eighth N site, N(8) is bonded in a distorted single-bond geometry to one Cs(2) and one C(4) atom. In the ninth N site, N(9) is bonded in a distorted water-like geometry to one C(3), one C(4), and one N(11) atom. The N(9)-N(11) bond length is 1.39 Å. In the tenth N site, N(10) is bonded in a distorted trigonal planar geometry to one Cs(1), one C(4), one H(3), and one H(4) atom. The N(10)-H(3) bond length is 1.04 Å. The N(10)-H(4) bond length is 1.02 Å. In the eleventh N site, N(11) is bonded in a 3-coordinate geometry to one Cs(1), one N(12), and one N(9) atom. The N(11)-N(12) bond length is 1.34 Å. In the twelfth N site, N(12) is bonded in a trigonal planar geometry to one N(11), one O(3), and one O(4) atom. The N(12)-O(3) bond length is 1.27 Å. The N(12)-O(4) bond length is 1.27 Å. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one N(4) atom. In the second H site, H(2) is bonded in a single-bond geometry to one N(4) atom. In the third H site, H(3) is bonded in a single-bond geometry to one N(10) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one N(10) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Cs(1), one Cs(2), and one N(6) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Cs(2), two equivalent Cs(1), and one N(6) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Cs(1), one Cs(2), and one N(12) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Cs(1), two equivalent Cs(2), and one N(12) atom. Linkers: 3 Nc1nnc(-c2nnc(N)n2[N][N+](=O)[O-])n1[N][N+](=O)[O-]. Metal clusters: 8 [Cs]. The MOF has largest included sphere 2.35 A, density 2.66 g/cm3, surface area 2712.31 m2/g, accessible volume 0.08 cm3/g