NiH8(C7N4)2 crystallizes in the monoclinic C2/c space group. Ni(1) is bonded in a distorted octahedral geometry to two equivalent N(1), two equivalent N(3), and two equivalent N(4) atoms. Both Ni(1)-N(1) bond lengths are 2.04 Å. Both Ni(1)-N(3) bond lengths are 2.51 Å. Both Ni(1)-N(4) bond lengths are 2.07 Å. There are seven inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one N(1) and one N(3) atom. The C(1)-N(1) bond length is 1.34 Å. The C(1)-N(3) bond length is 1.35 Å. In the second C site, C(2) is bonded in a distorted trigonal planar geometry to one C(3), one N(2), and one N(3) atom. The C(2)-C(3) bond length is 1.46 Å. The C(2)-N(2) bond length is 1.35 Å. The C(2)-N(3) bond length is 1.37 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one C(2), one C(4), and one C(7) atom. The C(3)-C(4) bond length is 1.40 Å. The C(3)-C(7) bond length is 1.41 Å. In the fourth C site, C(4) is bonded in a distorted trigonal planar geometry to one C(3), one C(5), and one H(1) atom. The C(4)-C(5) bond length is 1.40 Å. The C(4)-H(1) bond length is 1.09 Å. In the fifth C site, C(5) is bonded in a distorted single-bond geometry to one C(4), one C(6), and one H(2) atom. The C(5)-C(6) bond length is 1.39 Å. The C(5)-H(2) bond length is 1.09 Å. In the sixth C site, C(6) is bonded in a distorted trigonal planar geometry to one C(5), one N(4), and one H(3) atom. The C(6)-N(4) bond length is 1.35 Å. The C(6)-H(3) bond length is 1.09 Å. In the seventh C site, C(7) is bonded in a distorted trigonal planar geometry to one C(3), one N(4), and one H(4) atom. The C(7)-N(4) bond length is 1.34 Å. The C(7)-H(4) bond length is 1.09 Å. There are four inequivalent N sites. In the first N site, N(2) is bonded in a water-like geometry to one C(2) and one N(1) atom. The N(2)-N(1) bond length is 1.36 Å. In the second N site, N(3) is bonded in a distorted water-like geometry to one Ni(1), one C(1), and one C(2) atom. In the third N site, N(4) is bonded in a trigonal planar geometry to one Ni(1), one C(6), and one C(7) atom. In the fourth N site, N(1) is bonded in a distorted trigonal planar geometry to one Ni(1), one C(1), and one N(2) atom. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(4) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(5) 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. Linkers: 1 [CH]=C[C]C1=NN=C(C2=NN=C(c3cccnc3)[N]2)[N]1 ,1 [c]1[c]ncc(C2=N[N]C(C3=NC(c4cccnc4)=N[N]3)=N2)c1 ,2 [C]/C=[C]/C1=NN=C(C2=NN=C(c3cccnc3)[N]2)[N]1 ,1 c1cncc(C2=NN=C(C3=NN=C(c4cccnc4)[N]3)[N]2)c1 ,1 [c]1[c]ncc(C2=NN=C(C3=NN=C(c4cccnc4)[N]3)[N]2)c1 ,1 [CH]=C[C]C1=NN=C(C2=NC(c3cccnc3)=N[N]2)[N]1 ,1 c1cncc(C2=NN=C(C3=NC(c4cccnc4)=N[N]3)[N]2)c1 ,1 [CH]/C=[C]/C1=N[N]C(C2=NN=C(c3cccnc3)[N]2)=N1 ,1 [CH]/C=[C]/C1=NN=C(C2=NN=C(c3cccnc3)[N]2)[N]1. Metal clusters: 2 [Ni]. The MOF has largest included sphere 2.46 A, density 1.69 g/cm3, surface area 3814.01 m2/g, accessible volume 0.18 cm3/g