NaC4N5H2O crystallizes in the monoclinic P2_1/c space group. Na(1) is bonded in a 6-coordinate geometry to one N(3), one N(4), two equivalent N(5), and two equivalent O(1) atoms. The Na(1)-N(3) bond length is 2.58 Å. The Na(1)-N(4) bond length is 2.43 Å. There is one shorter (2.49 Å) and one longer (2.89 Å) Na(1)-N(5) bond length. There is one shorter (2.32 Å) and one longer (2.42 Å) Na(1)-O(1) bond length. There are four inequivalent C sites. In the first C site, C(1) is bonded in a distorted single-bond geometry to one C(2), one C(3), and one N(3) atom. The C(1)-C(2) bond length is 1.41 Å. The C(1)-C(3) bond length is 1.41 Å. The C(1)-N(3) bond length is 1.36 Å. In the second C site, C(2) is bonded in a distorted single-bond geometry to one C(1), one C(4), and one N(1) atom. The C(2)-C(4) bond length is 1.41 Å. The C(2)-N(1) bond length is 1.36 Å. In the third C site, C(3) is bonded in a distorted linear geometry to one C(1) and one N(5) atom. The C(3)-N(5) bond length is 1.17 Å. In the fourth C site, C(4) is bonded in a linear geometry to one C(2) and one N(4) atom. The C(4)-N(4) bond length is 1.17 Å. There are five inequivalent N sites. In the first N site, N(2) is bonded in a 2-coordinate geometry to one N(1) and one N(3) atom. The N(2)-N(1) bond length is 1.33 Å. The N(2)-N(3) bond length is 1.33 Å. In the second N site, N(3) is bonded in a 3-coordinate geometry to one Na(1), one C(1), and one N(2) atom. In the third N site, N(4) is bonded in a linear geometry to one Na(1) and one C(4) atom. In the fourth N site, N(5) is bonded in a 3-coordinate geometry to two equivalent Na(1) and one C(3) atom. In the fifth N site, N(1) is bonded in a distorted single-bond geometry to one C(2), one N(2), and one H(1) atom. The N(1)-H(1) bond length is 1.78 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one N(1) and one O(1) atom. The H(1)-O(1) bond length is 1.00 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(1) atom. The H(2)-O(1) bond length is 0.99 Å. O(1) is bonded in a distorted water-like geometry to two equivalent Na(1), one H(1), and one H(2) atom. Linkers: 2 N#C[C]1N=NN=C1C#N ,1 N#CC1=N[N]N=C1C#N ,1 N#CC1=C(C#N)N=N[N]1 ,4 O. Metal clusters: 4 [Na]. The MOF has largest included sphere 2.65 A, density 1.47 g/cm3, surface area 4069.82 m2/g, accessible volume 0.16 cm3/g