CdH4(CN)8 crystallizes in the monoclinic P2_1/c space group. Cd(1) is bonded in a distorted trigonal bipyramidal geometry to one N(2), one N(3), one N(5), one N(6), and one N(7) atom. The Cd(1)-N(2) bond length is 2.25 Å. The Cd(1)-N(3) bond length is 2.47 Å. The Cd(1)-N(5) bond length is 2.40 Å. The Cd(1)-N(6) bond length is 2.39 Å. The Cd(1)-N(7) bond length is 2.26 Å. There are eight inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one N(2), one N(6), and one H(1) atom. The C(1)-N(2) bond length is 1.35 Å. The C(1)-N(6) bond length is 1.35 Å. The C(1)-H(1) bond length is 1.09 Å. In the second C site, C(2) is bonded in a distorted trigonal planar geometry to one C(4), one C(8), and one N(1) atom. The C(2)-C(4) bond length is 1.41 Å. The C(2)-C(8) bond length is 1.45 Å. The C(2)-N(1) bond length is 1.35 Å. In the third C site, C(3) is bonded in a distorted bent 120 degrees geometry to one N(1) and one H(2) atom. The C(3)-N(1) bond length is 1.34 Å. The C(3)-H(2) bond length is 1.09 Å. In the fourth C site, C(4) is bonded in a distorted bent 120 degrees geometry to one C(2), one N(3), and one H(3) atom. The C(4)-N(3) bond length is 1.33 Å. The C(4)-H(3) bond length is 1.09 Å. In the fifth C site, C(5) is bonded in a distorted bent 120 degrees geometry to one N(3) and one H(4) atom. The C(5)-N(3) bond length is 1.35 Å. The C(5)-H(4) bond length is 1.09 Å. In the sixth C site, C(6) is bonded in a distorted trigonal planar geometry to one C(7), one N(4), and one N(6) atom. The C(6)-C(7) bond length is 1.44 Å. The C(6)-N(4) bond length is 1.33 Å. The C(6)-N(6) bond length is 1.37 Å. In the seventh C site, C(7) is bonded in a distorted water-like geometry to one C(6), one N(5), and one N(7) atom. The C(7)-N(5) bond length is 1.35 Å. The C(7)-N(7) bond length is 1.35 Å. In the eighth C site, C(8) is bonded in a distorted bent 120 degrees geometry to one C(2), one N(7), and one N(8) atom. The C(8)-N(7) bond length is 1.36 Å. The C(8)-N(8) bond length is 1.35 Å. There are eight inequivalent N sites. In the first N site, N(1) is bonded in a bent 120 degrees geometry to one C(2) and one C(3) atom. In the second N site, N(2) is bonded in a distorted trigonal planar geometry to one Cd(1), one C(1), and one N(4) atom. The N(2)-N(4) bond length is 1.37 Å. In the third N site, N(3) is bonded in a trigonal planar geometry to one Cd(1), one C(4), and one C(5) atom. In the fourth N site, N(4) is bonded in a distorted water-like geometry to one C(6) and one N(2) atom. In the fifth N site, N(5) is bonded in a 3-coordinate geometry to one Cd(1), one C(7), and one N(8) atom. The N(5)-N(8) bond length is 1.36 Å. In the sixth N site, N(6) is bonded in a distorted trigonal non-coplanar geometry to one Cd(1), one C(1), and one C(6) atom. In the seventh N site, N(7) is bonded in a distorted trigonal planar geometry to one Cd(1), one C(7), and one C(8) atom. In the eighth N site, N(8) is bonded in a water-like geometry to one C(8) and one N(5) 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(3) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(4) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(5) atom. Linkers: 2 [N]1C(=NN=C1C1=[N]=CN=N1)c1cnccn1 ,1 C1=NC(C2=N[N]C(c3cnccn3)=N2)=N[N]1 ,1 [N]1N=C(N=C1c1cnccn1)C1=[N]=CN=N1. Metal clusters: 4 [Cd]. The MOF has largest included sphere 3.63 A, density 1.77 g/cm3, surface area 3312.72 m2/g, accessible volume 0.21 cm3/g