CdH16(C5N3)4 crystallizes in the orthorhombic Fddd space group. Cd(1) is bonded in a square co-planar geometry to four equivalent N(3) atoms. All Cd(1)-N(3) bond lengths are 2.30 Å. There are five inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one N(2), one N(3), and one H(1) atom. The C(1)-N(2) bond length is 1.31 Å. The C(1)-N(3) bond length is 1.36 Å. The C(1)-H(1) bond length is 0.95 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one N(1), one N(3), and one H(2) atom. The C(2)-N(1) bond length is 1.32 Å. The C(2)-N(3) bond length is 1.32 Å. The C(2)-H(2) bond length is 0.95 Å. In the third C site, C(3) is bonded in a 3-coordinate geometry to one C(4), one C(5), one N(1), one H(3), and one H(4) atom. The C(3)-C(4) bond length is 1.51 Å. The C(3)-C(5) bond length is 1.53 Å. The C(3)-N(1) bond length is 1.46 Å. The C(3)-H(3) bond length is 0.89 Å. The C(3)-H(4) bond length is 0.86 Å. In the fourth C site, C(4) is bonded in a 3-coordinate geometry to one C(3) and two equivalent C(5) atoms. There is one shorter (0.89 Å) and one longer (1.21 Å) C(4)-C(5) bond length. In the fifth C site, C(5) is bonded in a 3-coordinate geometry to one C(3) and two equivalent C(4) atoms. There are three inequivalent N sites. In the first N site, N(1) is bonded in a distorted trigonal planar geometry to one C(2), one C(3), and one N(2) atom. The N(1)-N(2) bond length is 1.35 Å. In the second N site, N(2) is bonded in a water-like geometry to one C(1) and one N(1) atom. In the third N site, N(3) is bonded in a distorted trigonal planar geometry to one Cd(1), one C(1), and one C(2) atom. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(2) 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(3) atom. Linkers: 15 [CH2]n1cncn1.[C]1[C][C](Cn2cncn2)[C]1 ,1 [C]1[C][C](Cn2cncn2)[C]1Cn1cncn1. Metal clusters: 8 [Cd]. The MOF has largest included sphere 3.84 A, density 1.20 g/cm3, surface area 4453.93 m2/g, accessible volume 0.47 cm3/g