FeH8(C3N)4 crystallizes in the orthorhombic C222_1 space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a tetrahedral geometry to two equivalent N(1) and two equivalent N(3) atoms. Both Fe(1)-N(1) bond lengths are 2.00 Å. Both Fe(1)-N(3) bond lengths are 2.00 Å. In the second Fe site, Fe(2) is bonded in a tetrahedral geometry to two equivalent N(2) and two equivalent N(4) atoms. Both Fe(2)-N(2) bond lengths are 2.00 Å. Both Fe(2)-N(4) bond lengths are 2.00 Å. There are twelve inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one C(2), one N(1), and one H(1) atom. The C(1)-C(2) bond length is 1.41 Å. The C(1)-N(1) 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 trigonal planar geometry to one C(1), one C(3), and one C(4) atom. The C(2)-C(3) bond length is 1.41 Å. The C(2)-C(4) bond length is 1.46 Å. In the third C site, C(3) is bonded in a distorted bent 120 degrees geometry to one C(2), one N(2), and one H(2) atom. The C(3)-N(2) bond length is 1.35 Å. The C(3)-H(2) bond length is 1.09 Å. In the fourth C site, C(4) is bonded in a trigonal planar geometry to one C(2), one C(5), and one C(9) atom. The C(4)-C(5) bond length is 1.41 Å. The C(4)-C(9) bond length is 1.41 Å. In the fifth C site, C(5) is bonded in a distorted single-bond geometry to one C(4) and one H(3) atom. The C(5)-H(3) bond length is 1.09 Å. In the sixth C site, C(6) is bonded in a distorted single-bond geometry to one C(7) and one H(4) atom. The C(6)-C(7) bond length is 1.41 Å. The C(6)-H(4) bond length is 1.09 Å. In the seventh C site, C(7) is bonded in a trigonal planar geometry to one C(11), one C(6), and one C(8) atom. The C(7)-C(11) bond length is 1.46 Å. The C(7)-C(8) bond length is 1.41 Å. In the eighth C site, C(8) is bonded in a distorted single-bond geometry to one C(7), one C(9), and one H(5) atom. The C(8)-C(9) bond length is 1.39 Å. The C(8)-H(5) bond length is 1.09 Å. In the ninth C site, C(9) is bonded in a distorted trigonal planar geometry to one C(4), one C(8), and one H(6) atom. The C(9)-H(6) bond length is 1.09 Å. In the tenth C site, C(10) is bonded in a distorted bent 120 degrees geometry to one C(11), one N(3), and one H(7) atom. The C(10)-C(11) bond length is 1.41 Å. The C(10)-N(3) bond length is 1.35 Å. The C(10)-H(7) bond length is 1.09 Å. In the eleventh C site, C(11) is bonded in a trigonal planar geometry to one C(10), one C(12), and one C(7) atom. The C(11)-C(12) bond length is 1.41 Å. In the twelfth C site, C(12) is bonded in a distorted bent 120 degrees geometry to one C(11), one N(4), and one H(8) atom. The C(12)-N(4) bond length is 1.35 Å. The C(12)-H(8) bond length is 1.09 Å. There are four inequivalent N sites. In the first N site, N(1) is bonded in a distorted trigonal planar geometry to one Fe(1), one C(1), and one N(2) atom. The N(1)-N(2) bond length is 1.37 Å. In the second N site, N(2) is bonded in a distorted trigonal planar geometry to one Fe(2), one C(3), and one N(1) atom. In the third N site, N(3) is bonded in a distorted trigonal planar geometry to one Fe(1), one C(10), and one N(4) atom. The N(3)-N(4) bond length is 1.37 Å. In the fourth N site, N(4) is bonded in a distorted trigonal planar geometry to one Fe(2), one C(12), and one N(3) atom. There are eight 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(5) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(6) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(8) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one C(9) atom. In the seventh H site, H(7) is bonded in a single-bond geometry to one C(10) atom. In the eighth H site, H(8) is bonded in a single-bond geometry to one C(12) atom. Linkers: 1 C1=N[N]C=C1c1ccc(C2=C[N]N=C2)cc1 ,2 C1=NN=C[C]1c1ccc([C]2C=NN=C2)cc1 ,1 C1=N[N]C=C1c1ccc([C]2C=NN=C2)cc1. Metal clusters: 4 [Fe]. The MOF has largest included sphere 9.78 A, density 0.73 g/cm3, surface area 4649.43 m2/g, accessible volume 0.89 cm3/g