Cu5H9(C3N4)9 crystallizes in the orthorhombic Fddd space group. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a tetrahedral geometry to one N(13), one N(16), one N(3), and one N(5) atom. The Cu(1)-N(13) bond length is 2.01 Å. The Cu(1)-N(16) bond length is 2.10 Å. The Cu(1)-N(3) bond length is 1.98 Å. The Cu(1)-N(5) bond length is 2.06 Å. In the second Cu site, Cu(2) is bonded in a tetrahedral geometry to one N(12), one N(18), one N(6), and one N(9) atom. The Cu(2)-N(12) bond length is 2.06 Å. The Cu(2)-N(18) bond length is 2.07 Å. The Cu(2)-N(6) bond length is 1.96 Å. The Cu(2)-N(9) bond length is 2.07 Å. In the third Cu site, Cu(3) is bonded in a tetrahedral geometry to two equivalent N(17) and two equivalent N(2) atoms. Both Cu(3)-N(17) bond lengths are 2.07 Å. Both Cu(3)-N(2) bond lengths are 2.07 Å. There are fifteen inequivalent C sites. In the first C site, C(13) is bonded in a trigonal planar geometry to one C(15) and two equivalent C(7) atoms. The C(13)-C(15) bond length is 1.47 Å. Both C(13)-C(7) bond lengths are 1.39 Å. In the second C site, C(14) is bonded in a distorted single-bond geometry to two equivalent C(8) and one H(5) atom. Both C(14)-C(8) bond lengths are 1.38 Å. The C(14)-H(5) bond length is 0.93 Å. In the third C site, C(15) is bonded in a distorted trigonal planar geometry to one C(13) and two equivalent N(13) atoms. Both C(15)-N(13) bond lengths are 1.34 Å. In the fourth C site, C(1) is bonded in a trigonal planar geometry to one C(2), one C(6), and one C(9) atom. The C(1)-C(2) bond length is 1.38 Å. The C(1)-C(6) bond length is 1.38 Å. The C(1)-C(9) bond length is 1.46 Å. In the fifth C site, C(2) is bonded in a single-bond geometry to one C(1), one C(3), and one H(1) atom. The C(2)-C(3) bond length is 1.39 Å. The C(2)-H(1) bond length is 0.93 Å. In the sixth C site, C(3) is bonded in a trigonal planar geometry to one C(10), one C(2), and one C(4) atom. The C(3)-C(10) bond length is 1.46 Å. The C(3)-C(4) bond length is 1.40 Å. In the seventh C site, C(4) is bonded in a distorted single-bond geometry to one C(3), one C(5), and one H(2) atom. The C(4)-C(5) bond length is 1.38 Å. The C(4)-H(2) bond length is 0.93 Å. In the eighth C site, C(5) is bonded in a trigonal planar geometry to one C(12), one C(4), and one C(6) atom. The C(5)-C(12) bond length is 1.47 Å. The C(5)-C(6) bond length is 1.40 Å. In the ninth C site, C(6) is bonded in a distorted single-bond geometry to one C(1), one C(5), and one H(3) atom. The C(6)-H(3) bond length is 0.93 Å. In the tenth C site, C(7) is bonded in a distorted single-bond geometry to one C(13), one C(8), and one H(4) atom. The C(7)-C(8) bond length is 1.39 Å. The C(7)-H(4) bond length is 0.93 Å. In the eleventh C site, C(8) is bonded in a trigonal planar geometry to one C(11), one C(14), and one C(7) atom. The C(8)-C(11) bond length is 1.46 Å. In the twelfth C site, C(9) is bonded in a distorted water-like geometry to one C(1), one N(1), and one N(2) atom. The C(9)-N(1) bond length is 1.33 Å. The C(9)-N(2) bond length is 1.33 Å. In the thirteenth C site, C(10) is bonded in a distorted water-like geometry to one C(3), one N(5), and one N(8) atom. The C(10)-N(5) bond length is 1.33 Å. The C(10)-N(8) bond length is 1.33 Å. In the fourteenth C site, C(11) is bonded in a 3-coordinate geometry to one C(8), one N(14), and one N(17) atom. The C(11)-N(14) bond length is 1.33 Å. The C(11)-N(17) bond length is 1.33 Å. In the fifteenth C site, C(12) is bonded in a distorted trigonal planar geometry to one C(5), one N(11), and one N(18) atom. The C(12)-N(11) bond length is 1.34 Å. The C(12)-N(18) bond length is 1.35 Å. There are eighteen inequivalent N sites. In the first N site, N(1) is bonded in a single-bond geometry to one C(9) atom. In the second N site, N(2) is bonded in a distorted trigonal planar geometry to one Cu(3), one C(9), and one N(3) atom. The N(2)-N(3) bond length is 1.33 Å. In the third N site, N(3) is bonded in a distorted trigonal planar geometry to one Cu(1), one N(2), and one N(4) atom. The N(3)-N(4) bond length is 1.33 Å. In the fourth N site, N(4) is bonded in a single-bond geometry to one N(3) atom. In the fifth N site, N(5) is bonded in a distorted trigonal planar geometry to one Cu(1), one C(10), and one N(6) atom. The N(5)-N(6) bond length is 1.33 Å. In the sixth N site, N(6) is bonded in a distorted trigonal planar geometry to one Cu(2), one N(5), and one N(7) atom. The N(6)-N(7) bond length is 1.33 Å. In the seventh N site, N(7) is bonded in a water-like geometry to one N(6) and one N(8) atom. The N(7)-N(8) bond length is 1.33 Å. In the eighth N site, N(8) is bonded in a single-bond geometry to one C(10) and one N(7) atom. In the ninth N site, N(9) is bonded in a distorted trigonal planar geometry to one Cu(2), one N(10), and one N(18) atom. The N(9)-N(10) bond length is 1.31 Å. The N(9)-N(18) bond length is 1.36 Å. In the tenth N site, N(10) is bonded in a distorted single-bond geometry to one N(9) atom. In the eleventh N site, N(11) is bonded in a single-bond geometry to one C(12) atom. In the twelfth N site, N(12) is bonded in a distorted trigonal planar geometry to one Cu(2), one N(12), and one N(13) atom. The N(12)-N(12) bond length is 1.31 Å. The N(12)-N(13) bond length is 1.35 Å. In the thirteenth N site, N(13) is bonded in a 3-coordinate geometry to one Cu(1), one C(15), and one N(12) atom. In the fourteenth N site, N(14) is bonded in a distorted single-bond geometry to one C(11) and one N(15) atom. The N(14)-N(15) bond length is 1.33 Å. In the fifteenth N site, N(15) is bonded in a distorted water-like geometry to one N(14) and one N(16) atom. The N(15)-N(16) bond length is 1.33 Å. In the sixteenth N site, N(16) is bonded in a distorted trigonal planar geometry to one Cu(1), one N(15), and one N(17) atom. The N(16)-N(17) bond length is 1.33 Å. In the seventeenth N site, N(17) is bonded in a distorted trigonal planar geometry to one Cu(3), one C(11), and one N(16) atom. In the eighteenth N site, N(18) is bonded in a distorted trigonal planar geometry to one Cu(2), one C(12), and one N(9) atom. There are five inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(2) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(4) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(6) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(7) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(14) atom. Linkers: 14 c1c(C2=NN=N[N]2)cc(C2=NN=N[N]2)cc1C1=NN=N[N]1 ,25 c1c(C2=NN=N[N]2)cc(C2=N[N]N=N2)cc1C1=NN=N[N]1 ,9 c1c(C2=NN=N[N]2)cc(C2=N[N]N=N2)cc1C1=N[N]N=N1. Metal clusters: 80 [Cu]. The MOF has largest included sphere 9.64 A, density 0.97 g/cm3, surface area 3492.83 m2/g, accessible volume 0.72 cm3/g