CoH4(CN)8 crystallizes in the tetragonal P4_12_12 space group. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded in a square pyramidal geometry to one N(11), one N(14), one N(16), one N(2), and one N(6) atom. The Co(1)-N(11) bond length is 2.14 Å. The Co(1)-N(14) bond length is 2.07 Å. The Co(1)-N(16) bond length is 2.22 Å. The Co(1)-N(2) bond length is 2.12 Å. The Co(1)-N(6) bond length is 2.09 Å. In the second Co site, Co(2) is bonded in an octahedral geometry to two equivalent N(4), two equivalent N(7), and two equivalent N(9) atoms. Both Co(2)-N(4) bond lengths are 2.13 Å. Both Co(2)-N(7) bond lengths are 2.08 Å. Both Co(2)-N(9) bond lengths are 2.14 Å. In the third Co site, Co(3) is bonded in a distorted see-saw-like geometry to two equivalent N(15) and two equivalent N(3) atoms. Both Co(3)-N(15) bond lengths are 2.10 Å. Both Co(3)-N(3) bond lengths are 2.20 Å. There are sixteen inequivalent C sites. In the first C site, C(16) is bonded in a distorted bent 120 degrees geometry to one C(4), one N(8), and one H(4) atom. The C(16)-C(4) bond length is 1.37 Å. The C(16)-N(8) bond length is 1.36 Å. The C(16)-H(4) bond length is 0.93 Å. In the second C site, C(1) is bonded in a distorted bent 120 degrees geometry to one N(2) and one N(5) atom. The C(1)-N(2) bond length is 1.34 Å. The C(1)-N(5) bond length is 1.33 Å. In the third C site, C(2) is bonded in a distorted trigonal planar geometry to one C(14), one N(3), and one H(3) atom. The C(2)-C(14) bond length is 1.34 Å. The C(2)-N(3) bond length is 1.36 Å. The C(2)-H(3) bond length is 0.93 Å. In the fourth C site, C(3) is bonded in a distorted trigonal planar geometry to one C(6), one N(12), and one H(1) atom. The C(3)-C(6) bond length is 1.41 Å. The C(3)-N(12) bond length is 1.33 Å. The C(3)-H(1) bond length is 0.93 Å. In the fifth C site, C(4) is bonded in a distorted trigonal planar geometry to one C(16), one C(9), and one N(16) atom. The C(4)-C(9) bond length is 1.47 Å. The C(4)-N(16) bond length is 1.35 Å. In the sixth C site, C(5) is bonded in a trigonal planar geometry to one N(13), one N(14), and one H(8) atom. The C(5)-N(13) bond length is 1.32 Å. The C(5)-N(14) bond length is 1.33 Å. The C(5)-H(8) bond length is 0.93 Å. In the seventh C site, C(6) is bonded in a distorted trigonal planar geometry to one C(12), one C(3), and one N(3) atom. The C(6)-C(12) bond length is 1.42 Å. The C(6)-N(3) bond length is 1.34 Å. In the eighth C site, C(7) is bonded in a trigonal planar geometry to one N(5), one N(7), and one H(6) atom. The C(7)-N(5) bond length is 1.38 Å. The C(7)-N(7) bond length is 1.32 Å. The C(7)-H(6) bond length is 0.93 Å. In the ninth C site, C(8) is bonded in a distorted bent 120 degrees geometry to one N(11) and one N(6) atom. The C(8)-N(11) bond length is 1.32 Å. The C(8)-N(6) bond length is 1.32 Å. In the tenth C site, C(9) is bonded in a distorted trigonal planar geometry to one C(4), one N(1), and one N(6) atom. The C(9)-N(1) bond length is 1.32 Å. The C(9)-N(6) bond length is 1.35 Å. In the eleventh C site, C(10) is bonded in a distorted bent 120 degrees geometry to one C(11), one N(8), and one H(2) atom. The C(10)-C(11) bond length is 1.40 Å. The C(10)-N(8) bond length is 1.29 Å. The C(10)-H(2) bond length is 0.93 Å. In the twelfth C site, C(11) is bonded in a distorted trigonal planar geometry to one C(10), one N(16), and one H(7) atom. The C(11)-N(16) bond length is 1.32 Å. The C(11)-H(7) bond length is 0.93 Å. In the thirteenth C site, C(12) is bonded in a distorted trigonal planar geometry to one C(6), one N(10), and one N(15) atom. The C(12)-N(10) bond length is 1.32 Å. The C(12)-N(15) bond length is 1.36 Å. In the fourteenth C site, C(13) is bonded in a distorted trigonal planar geometry to one C(15), one N(15), and one N(9) atom. The C(13)-C(15) bond length is 1.45 Å. The C(13)-N(15) bond length is 1.34 Å. The C(13)-N(9) bond length is 1.32 Å. In the fifteenth C site, C(14) is bonded in a distorted trigonal planar geometry to one C(2), one N(12), and one H(5) atom. The C(14)-N(12) bond length is 1.29 Å. The C(14)-H(5) bond length is 0.93 Å. In the sixteenth C site, C(15) is bonded in a 2-coordinate geometry to one C(13), one N(13), and one N(4) atom. The C(15)-N(13) bond length is 1.35 Å. The C(15)-N(4) bond length is 1.32 Å. There are sixteen inequivalent N sites. In the first N site, N(16) is bonded in a trigonal planar geometry to one Co(1), one C(11), and one C(4) atom. In the second N site, N(3) is bonded in a trigonal planar geometry to one Co(3), one C(2), and one C(6) atom. In the third N site, N(5) is bonded in a water-like geometry to one C(1) and one C(7) atom. In the fourth N site, N(7) is bonded in a distorted trigonal planar geometry to one Co(2), one C(7), and one N(2) atom. The N(7)-N(2) bond length is 1.37 Å. In the fifth N site, N(8) is bonded in a bent 120 degrees geometry to one C(10) and one C(16) atom. In the sixth N site, N(1) is bonded in a distorted single-bond geometry to one C(9) and one N(11) atom. The N(1)-N(11) bond length is 1.36 Å. In the seventh N site, N(2) is bonded in a 3-coordinate geometry to one Co(1), one C(1), and one N(7) atom. In the eighth N site, N(4) is bonded in a 3-coordinate geometry to one Co(2), one C(15), and one N(14) atom. The N(4)-N(14) bond length is 1.37 Å. In the ninth N site, N(6) is bonded in a distorted trigonal planar geometry to one Co(1), one C(8), and one C(9) atom. In the tenth N site, N(9) is bonded in a 3-coordinate geometry to one Co(2), one C(13), and one N(10) atom. The N(9)-N(10) bond length is 1.39 Å. In the eleventh N site, N(10) is bonded in a distorted water-like geometry to one C(12) and one N(9) atom. In the twelfth N site, N(11) is bonded in a 3-coordinate geometry to one Co(1), one C(8), and one N(1) atom. In the thirteenth N site, N(12) is bonded in a bent 120 degrees geometry to one C(14) and one C(3) atom. In the fourteenth N site, N(13) is bonded in a water-like geometry to one C(15) and one C(5) atom. In the fifteenth N site, N(14) is bonded in a distorted trigonal planar geometry to one Co(1), one C(5), and one N(4) atom. In the sixteenth N site, N(15) is bonded in a distorted trigonal planar geometry to one Co(3), one C(12), and one C(13) atom. There are eight inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(3) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(10) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(2) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(16) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(14) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one C(7) atom. In the seventh H site, H(7) is bonded in a single-bond geometry to one C(11) atom. In the eighth H site, H(8) is bonded in a single-bond geometry to one C(5) atom. Linkers: 1 C1=NC(C2=NN=C(c3cnccn3)[N]2)=N[N]1 ,1 [N]1N=CN=C1C1=[N]=C(N=N1)c1cnccn1 ,1 [CH]1C=NC=C2c3nnc(C4=NC=N[N]4)n3[Co@@]3(N4C=CN=C[C]4c4nnc(C5=NC=N[N]5)n43)N12 ,1 N1=C[C]2N(C=C1)[Co@@]1(n3c2nnc3C2=[N]=CN=N2)N2[CH]C=NC=C2c2n1c(nn2)C1=NN=C[N]1 ,1 N1=NC(=[N]=C1)c1nnc2n1[Co@]1(n3c(nnc3C3=CN=C[CH]N13)C1=[N]=CN=N1)N1[C]2C=NC=C1 ,2 [N]1N=C(N=C1c1cnccn1)C1=[N]=CN=N1 ,1 [N]1C=NN=C1C1=[N]=C(N=N1)c1cnccn1 ,1 C1=NN=C(C2=NN=C(c3cnccn3)[N]2)[N]1 ,1 C1=N[N]C(C2=NN=C(c3cnccn3)[N]2)=N1 ,1 C1=[N]=C(N=N1)C1=[N]=C(N=N1)c1cnccn1 ,1 [CH]1C=NC=C2c3nnc(C4=N[N]C=N4)n3[Co@@]3(N4C=CN=C[C]4c4nnc(C5=NN=C[N]5)n43)N12. Metal clusters: 4 [N]1[N][Co]2([N][N][Co]=N[N]2)[N]N=[Co]1. The MOF has largest included sphere 4.71 A, density 1.22 g/cm3, surface area 3866.84 m2/g, accessible volume 0.45 cm3/g