Cr8Fe3N8 crystallizes in the monoclinic C2/m space group. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a square co-planar geometry to one N(1), one N(2), and two equivalent N(4) atoms. In the second Cr site, Cr(2) is bonded in a rectangular see-saw-like geometry to one N(3), one N(4), and two equivalent N(2) atoms. In the third Cr site, Cr(3) is bonded to one N(3), two equivalent N(1), and two equivalent N(4) atoms to form a mixture of distorted corner and edge-sharing CrN5 square pyramids. In the fourth Cr site, Cr(4) is bonded to one N(1), one N(2), and three equivalent N(3) atoms to form a mixture of corner and edge-sharing CrN5 square pyramids. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a linear geometry to two equivalent N(4) atoms. In the second Fe site, Fe(2) is bonded in a distorted trigonal planar geometry to one N(1), one N(2), and one N(3) atom. There are four inequivalent N sites. In the first N site, N(1) is bonded to one Cr(1), one Cr(4), two equivalent Cr(3), and one Fe(2) atom to form distorted NCr4Fe trigonal bipyramids that share corners with two equivalent N(4)Cr5Fe octahedra, corners with two equivalent N(1)Cr4Fe trigonal bipyramids, corners with three equivalent N(2)Cr4Fe trigonal bipyramids, edges with two equivalent N(4)Cr5Fe octahedra, and edges with three equivalent N(3)Cr5Fe octahedra. The corner-sharing octahedral tilt angles are 78°. In the second N site, N(2) is bonded to one Cr(1), one Cr(4), two equivalent Cr(2), and one Fe(2) atom to form NCr4Fe trigonal bipyramids that share corners with two equivalent N(3)Cr5Fe octahedra, corners with two equivalent N(2)Cr4Fe trigonal bipyramids, corners with three equivalent N(1)Cr4Fe trigonal bipyramids, edges with two equivalent N(3)Cr5Fe octahedra, and edges with two equivalent N(4)Cr5Fe octahedra. The corner-sharing octahedral tilt angles range from 9-51°. In the third N site, N(3) is bonded to one Cr(2), one Cr(3), three equivalent Cr(4), and one Fe(2) atom to form NCr5Fe octahedra that share corners with two equivalent N(3)Cr5Fe octahedra, corners with three equivalent N(4)Cr5Fe octahedra, corners with two equivalent N(2)Cr4Fe trigonal bipyramids, edges with two equivalent N(3)Cr5Fe octahedra, edges with two equivalent N(2)Cr4Fe trigonal bipyramids, and edges with three equivalent N(1)Cr4Fe trigonal bipyramids. The corner-sharing octahedral tilt angles range from 15-54°. In the fourth N site, N(4) is bonded to one Cr(2), two equivalent Cr(1), two equivalent Cr(3), and one Fe(1) atom to form NCr5Fe octahedra that share corners with three equivalent N(3)Cr5Fe octahedra, corners with three equivalent N(4)Cr5Fe octahedra, corners with two equivalent N(1)Cr4Fe trigonal bipyramids,  an edgeedge with one N(4)Cr5Fe octahedra, edges with two equivalent N(1)Cr4Fe trigonal bipyramids, and edges with two equivalent N(2)Cr4Fe trigonal bipyramids. The corner-sharing octahedral tilt angles range from 0-54°.
Cr8Fe3N8 crystallizes in the monoclinic C2/m space group. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a square co-planar geometry to one N(1), one N(2), and two equivalent N(4) atoms. The Cr(1)-N(1) bond length is 2.08 Å. The Cr(1)-N(2) bond length is 2.00 Å. Both Cr(1)-N(4) bond lengths are 1.98 Å. In the second Cr site, Cr(2) is bonded in a rectangular see-saw-like geometry to one N(3), one N(4), and two equivalent N(2) atoms. The Cr(2)-N(3) bond length is 1.98 Å. The Cr(2)-N(4) bond length is 1.95 Å. Both Cr(2)-N(2) bond lengths are 1.97 Å. In the third Cr site, Cr(3) is bonded to one N(3), two equivalent N(1), and two equivalent N(4) atoms to form a mixture of distorted corner and edge-sharing CrN5 square pyramids. The Cr(3)-N(3) bond length is 2.18 Å. Both Cr(3)-N(1) bond lengths are 2.01 Å. There is one shorter (1.95 Å) and one longer (2.14 Å) Cr(3)-N(4) bond length. In the fourth Cr site, Cr(4) is bonded to one N(1), one N(2), and three equivalent N(3) atoms to form a mixture of corner and edge-sharing CrN5 square pyramids. The Cr(4)-N(1) bond length is 2.01 Å. The Cr(4)-N(2) bond length is 2.02 Å. There are two shorter (1.99 Å) and one longer (2.05 Å) Cr(4)-N(3) bond length. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a linear geometry to two equivalent N(4) atoms. Both Fe(1)-N(4) bond lengths are 1.88 Å. In the second Fe site, Fe(2) is bonded in a distorted trigonal planar geometry to one N(1), one N(2), and one N(3) atom. The Fe(2)-N(1) bond length is 1.87 Å. The Fe(2)-N(2) bond length is 1.84 Å. The Fe(2)-N(3) bond length is 1.94 Å. There are four inequivalent N sites. In the first N site, N(1) is bonded to one Cr(1), one Cr(4), two equivalent Cr(3), and one Fe(2) atom to form distorted NCr4Fe trigonal bipyramids that share corners with two equivalent N(4)Cr5Fe octahedra, corners with two equivalent N(1)Cr4Fe trigonal bipyramids, corners with three equivalent N(2)Cr4Fe trigonal bipyramids, edges with two equivalent N(4)Cr5Fe octahedra, and edges with three equivalent N(3)Cr5Fe octahedra. The corner-sharing octahedral tilt angles are 78°. In the second N site, N(2) is bonded to one Cr(1), one Cr(4), two equivalent Cr(2), and one Fe(2) atom to form NCr4Fe trigonal bipyramids that share corners with two equivalent N(3)Cr5Fe octahedra, corners with two equivalent N(2)Cr4Fe trigonal bipyramids, corners with three equivalent N(1)Cr4Fe trigonal bipyramids, edges with two equivalent N(3)Cr5Fe octahedra, and edges with two equivalent N(4)Cr5Fe octahedra. The corner-sharing octahedral tilt angles range from 9-51°. In the third N site, N(3) is bonded to one Cr(2), one Cr(3), three equivalent Cr(4), and one Fe(2) atom to form NCr5Fe octahedra that share corners with two equivalent N(3)Cr5Fe octahedra, corners with three equivalent N(4)Cr5Fe octahedra, corners with two equivalent N(2)Cr4Fe trigonal bipyramids, edges with two equivalent N(3)Cr5Fe octahedra, edges with two equivalent N(2)Cr4Fe trigonal bipyramids, and edges with three equivalent N(1)Cr4Fe trigonal bipyramids. The corner-sharing octahedral tilt angles range from 15-54°. In the fourth N site, N(4) is bonded to one Cr(2), two equivalent Cr(1), two equivalent Cr(3), and one Fe(1) atom to form NCr5Fe octahedra that share corners with three equivalent N(3)Cr5Fe octahedra, corners with three equivalent N(4)Cr5Fe octahedra, corners with two equivalent N(1)Cr4Fe trigonal bipyramids,  an edgeedge with one N(4)Cr5Fe octahedra, edges with two equivalent N(1)Cr4Fe trigonal bipyramids, and edges with two equivalent N(2)Cr4Fe trigonal bipyramids. The corner-sharing octahedral tilt angles range from 0-54°.