CdC2N4H3Br crystallizes in the orthorhombic P2_12_12_1 space group. Cd(1) is bonded to one N(1), one N(2), one N(3), one N(4), and two equivalent Br(1) atoms to form distorted corner-sharing CdBr2N4 octahedra. The corner-sharing octahedral tilt angles are 90°. The Cd(1)-N(1) bond length is 2.28 Å. The Cd(1)-N(2) bond length is 2.37 Å. The Cd(1)-N(3) bond length is 2.54 Å. The Cd(1)-N(4) bond length is 2.33 Å. There is one shorter (2.77 Å) and one longer (2.87 Å) Cd(1)-Br(1) bond length. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one N(2), one N(4), and one H(3) atom. The C(1)-N(2) bond length is 1.35 Å. The C(1)-N(4) bond length is 1.33 Å. The C(1)-H(3) bond length is 1.08 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one N(1), one N(2), and one N(3) atom. The C(2)-N(1) bond length is 1.34 Å. The C(2)-N(2) bond length is 1.35 Å. The C(2)-N(3) bond length is 1.41 Å. There are four inequivalent N sites. In the first N site, N(2) is bonded in a distorted trigonal planar geometry to one Cd(1), one C(1), and one C(2) atom. In the second N site, N(3) is bonded in a distorted trigonal non-coplanar geometry to one Cd(1), one C(2), one H(1), and one H(2) atom. The N(3)-H(1) bond length is 1.03 Å. The N(3)-H(2) bond length is 1.03 Å. In the third N site, N(4) is bonded in a distorted trigonal planar geometry to one Cd(1), one C(1), and one N(1) atom. The N(4)-N(1) bond length is 1.37 Å. In the fourth N site, N(1) is bonded in a 3-coordinate geometry to one Cd(1), one C(2), and one N(4) atom. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one N(3) atom. In the second H site, H(2) is bonded in a single-bond geometry to one N(3) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(1) atom. Br(1) is bonded in an L-shaped geometry to two equivalent Cd(1) atoms. Linkers: 1 NC1=NN=C[N]1 ,2 NC1=N[N]C=N1 ,1 NC1=NC=N[N]1. Metal clusters: 4 [Cd]. The MOF has largest included sphere 1.57 A, density 3.36 g/cm3, surface area 2307.96 m2/g, accessible volume 0.05 cm3/g