Fe3(CoN)8 crystallizes in the monoclinic C2/m space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a square co-planar geometry to two equivalent N(3) and two equivalent N(4) atoms. In the second Fe site, Fe(2) is bonded in a 3-coordinate geometry to one N(1), one N(2), and one N(3) atom. There are four inequivalent Co sites. In the first Co site, Co(1) is bonded in a 5-coordinate geometry to one N(2), two equivalent N(1), and two equivalent N(4) atoms. In the second Co site, Co(2) is bonded to one N(3), one N(4), and three equivalent N(2) atoms to form a mixture of corner and edge-sharing CoN5 square pyramids. In the third Co site, Co(3) is bonded to one N(3), two equivalent N(1), and two equivalent N(4) atoms to form a mixture of corner and edge-sharing CoN5 square pyramids. In the fourth Co site, Co(4) is bonded in a square co-planar geometry to one N(1), one N(2), and two equivalent N(3) atoms. There are four inequivalent N sites. In the first N site, N(1) is bonded in a 6-coordinate geometry to one Fe(2), one Co(4), two equivalent Co(1), and two equivalent Co(3) atoms. In the second N site, N(2) is bonded to one Fe(2), one Co(1), one Co(4), and three equivalent Co(2) atoms to form NFeCo5 octahedra that share  a cornercorner with one N(4)FeCo5 octahedra, corners with two equivalent N(2)FeCo5 octahedra, edges with two equivalent N(2)FeCo5 octahedra, edges with two equivalent N(4)FeCo5 octahedra, and edges with three equivalent N(3)Fe2Co4 octahedra. The corner-sharing octahedral tilt angles range from 11-12°. In the third N site, N(3) is bonded to one Fe(1), one Fe(2), one Co(2), one Co(3), and two equivalent Co(4) atoms to form NFe2Co4 octahedra that share  a cornercorner with one N(4)FeCo5 octahedra, corners with three equivalent N(3)Fe2Co4 octahedra, edges with two equivalent N(4)FeCo5 octahedra, and edges with three equivalent N(2)FeCo5 octahedra. The corner-sharing octahedral tilt angles range from 0-13°. In the fourth N site, N(4) is bonded to one Fe(1), one Co(2), two equivalent Co(1), and two equivalent Co(3) atoms to form NFeCo5 octahedra that share  a cornercorner with one N(3)Fe2Co4 octahedra,  a cornercorner with one N(2)FeCo5 octahedra, corners with three equivalent N(4)FeCo5 octahedra,  an edgeedge with one N(4)FeCo5 octahedra, edges with two equivalent N(3)Fe2Co4 octahedra, and edges with two equivalent N(2)FeCo5 octahedra. The corner-sharing octahedral tilt angles range from 0-14°.
Fe3(CoN)8 crystallizes in the monoclinic C2/m space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a square co-planar geometry to two equivalent N(3) and two equivalent N(4) atoms. Both Fe(1)-N(3) bond lengths are 2.04 Å. Both Fe(1)-N(4) bond lengths are 1.96 Å. In the second Fe site, Fe(2) is bonded in a 3-coordinate geometry to one N(1), one N(2), and one N(3) atom. The Fe(2)-N(1) bond length is 1.80 Å. The Fe(2)-N(2) bond length is 1.79 Å. The Fe(2)-N(3) bond length is 1.87 Å. There are four inequivalent Co sites. In the first Co site, Co(1) is bonded in a 5-coordinate geometry to one N(2), two equivalent N(1), and two equivalent N(4) atoms. The Co(1)-N(2) bond length is 2.14 Å. There is one shorter (1.85 Å) and one longer (2.37 Å) Co(1)-N(1) bond length. Both Co(1)-N(4) bond lengths are 1.97 Å. In the second Co site, Co(2) is bonded to one N(3), one N(4), and three equivalent N(2) atoms to form a mixture of corner and edge-sharing CoN5 square pyramids. The Co(2)-N(3) bond length is 1.98 Å. The Co(2)-N(4) bond length is 1.90 Å. There are two shorter (1.97 Å) and one longer (1.98 Å) Co(2)-N(2) bond length. In the third Co site, Co(3) is bonded to one N(3), two equivalent N(1), and two equivalent N(4) atoms to form a mixture of corner and edge-sharing CoN5 square pyramids. The Co(3)-N(3) bond length is 2.00 Å. Both Co(3)-N(1) bond lengths are 1.99 Å. There is one shorter (1.95 Å) and one longer (2.05 Å) Co(3)-N(4) bond length. In the fourth Co site, Co(4) is bonded in a square co-planar geometry to one N(1), one N(2), and two equivalent N(3) atoms. The Co(4)-N(1) bond length is 1.88 Å. The Co(4)-N(2) bond length is 1.93 Å. Both Co(4)-N(3) bond lengths are 1.97 Å. There are four inequivalent N sites. In the first N site, N(1) is bonded in a 6-coordinate geometry to one Fe(2), one Co(4), two equivalent Co(1), and two equivalent Co(3) atoms. In the second N site, N(2) is bonded to one Fe(2), one Co(1), one Co(4), and three equivalent Co(2) atoms to form NFeCo5 octahedra that share  a cornercorner with one N(4)FeCo5 octahedra, corners with two equivalent N(2)FeCo5 octahedra, edges with two equivalent N(2)FeCo5 octahedra, edges with two equivalent N(4)FeCo5 octahedra, and edges with three equivalent N(3)Fe2Co4 octahedra. The corner-sharing octahedral tilt angles range from 11-12°. In the third N site, N(3) is bonded to one Fe(1), one Fe(2), one Co(2), one Co(3), and two equivalent Co(4) atoms to form NFe2Co4 octahedra that share  a cornercorner with one N(4)FeCo5 octahedra, corners with three equivalent N(3)Fe2Co4 octahedra, edges with two equivalent N(4)FeCo5 octahedra, and edges with three equivalent N(2)FeCo5 octahedra. The corner-sharing octahedral tilt angles range from 0-13°. In the fourth N site, N(4) is bonded to one Fe(1), one Co(2), two equivalent Co(1), and two equivalent Co(3) atoms to form NFeCo5 octahedra that share  a cornercorner with one N(3)Fe2Co4 octahedra,  a cornercorner with one N(2)FeCo5 octahedra, corners with three equivalent N(4)FeCo5 octahedra,  an edgeedge with one N(4)FeCo5 octahedra, edges with two equivalent N(3)Fe2Co4 octahedra, and edges with two equivalent N(2)FeCo5 octahedra. The corner-sharing octahedral tilt angles range from 0-14°.