Cd5(C7N5)2 crystallizes in the orthorhombic Cccm space group. There are three inequivalent Cd sites. In the first Cd site, Cd(1) is bonded in an octahedral geometry to two equivalent N(3) and four equivalent N(1) atoms. Both Cd(1)-N(3) bond lengths are 2.24 Å. All Cd(1)-N(1) bond lengths are 2.40 Å. In the second Cd site, Cd(2) is bonded in a trigonal bipyramidal geometry to one C(3), two equivalent C(1), and two equivalent N(2) atoms. The Cd(2)-C(3) bond length is 2.25 Å. Both Cd(2)-C(1) bond lengths are 2.24 Å. Both Cd(2)-N(2) bond lengths are 2.42 Å. In the third Cd site, Cd(3) is bonded in a tetrahedral geometry to one C(4), one C(5), and two equivalent C(2) atoms. The Cd(3)-C(4) bond length is 2.23 Å. The Cd(3)-C(5) bond length is 2.21 Å. Both Cd(3)-C(2) bond lengths are 2.20 Å. There are five inequivalent C sites. In the first C site, C(3) is bonded in a distorted linear geometry to one Cd(2) and one C(3) atom. The C(3)-C(3) bond length is 1.11 Å. In the second C site, C(4) is bonded in a linear geometry to one Cd(3) and one N(3) atom. The C(4)-N(3) bond length is 1.12 Å. In the third C site, C(5) is bonded in a distorted single-bond geometry to one Cd(3) atom. In the fourth C site, C(1) is bonded in a linear geometry to one Cd(2) and one N(1) atom. The C(1)-N(1) bond length is 1.13 Å. In the fifth C site, C(2) is bonded in a linear geometry to one Cd(3) and one N(2) atom. The C(2)-N(2) bond length is 1.11 Å. There are three inequivalent N sites. In the first N site, N(1) is bonded in a linear geometry to one Cd(1) and one C(1) atom. In the second N site, N(2) is bonded in a linear geometry to one Cd(2) and one C(2) atom. In the third N site, N(3) is bonded in a linear geometry to one Cd(1) and one C(4) atom. Linkers: 1 [C]#[C]. Metal clusters: . The MOF has largest included sphere 4.79 A, density 1.40 g/cm3, surface area 3247.16 m2/g, accessible volume 0.44 cm3/g