Fe4CN4 crystallizes in the orthorhombic Pnma space group. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one N(1), one N(3), and two equivalent N(2) atoms to form distorted FeN4 tetrahedra that share corners with two equivalent Fe(1)N4 tetrahedra, corners with four equivalent Fe(4)N5 trigonal bipyramids, and edges with two equivalent Fe(3)CN5 octahedra. In the second Fe site, Fe(2) is bonded in a 5-coordinate geometry to one N(1), two equivalent N(2), and two equivalent N(3) atoms. In the third Fe site, Fe(3) is bonded to one C(1), one N(2), two equivalent N(1), and two equivalent N(4) atoms to form FeCN5 octahedra that share corners with four equivalent Fe(4)N5 trigonal bipyramids, edges with two equivalent Fe(3)CN5 octahedra, edges with two equivalent Fe(1)N4 tetrahedra,  an edgeedge with one Fe(4)N5 trigonal bipyramid, and  a faceface with one Fe(4)N5 trigonal bipyramid. In the fourth Fe site, Fe(4) is bonded to one N(2), two equivalent N(1), and two equivalent N(4) atoms to form distorted FeN5 trigonal bipyramids that share corners with four equivalent Fe(3)CN5 octahedra, corners with four equivalent Fe(1)N4 tetrahedra,  an edgeedge with one Fe(3)CN5 octahedra, edges with two equivalent Fe(4)N5 trigonal bipyramids, and  a faceface with one Fe(3)CN5 octahedra. The corner-sharing octahedral tilt angles range from 4-51°. C(1) is bonded in a trigonal planar geometry to one Fe(3), one N(3), and one N(4) atom. There are four inequivalent N sites. In the first N site, N(4) is bonded in a 5-coordinate geometry to two equivalent Fe(3), two equivalent Fe(4), and one C(1) atom. In the second N site, N(1) is bonded to one Fe(1), one Fe(2), two equivalent Fe(3), and two equivalent Fe(4) atoms to form distorted edge-sharing NFe6 octahedra. In the third N site, N(2) is bonded in a 6-coordinate geometry to one Fe(3), one Fe(4), two equivalent Fe(1), and two equivalent Fe(2) atoms. In the fourth N site, N(3) is bonded in a rectangular see-saw-like geometry to one Fe(1), two equivalent Fe(2), and one C(1) atom.
Fe4CN4 crystallizes in the orthorhombic Pnma space group. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one N(1), one N(3), and two equivalent N(2) atoms to form distorted FeN4 tetrahedra that share corners with two equivalent Fe(1)N4 tetrahedra, corners with four equivalent Fe(4)N5 trigonal bipyramids, and edges with two equivalent Fe(3)CN5 octahedra. The Fe(1)-N(1) bond length is 1.85 Å. The Fe(1)-N(3) bond length is 1.87 Å. Both Fe(1)-N(2) bond lengths are 1.95 Å. In the second Fe site, Fe(2) is bonded in a 5-coordinate geometry to one N(1), two equivalent N(2), and two equivalent N(3) atoms. The Fe(2)-N(1) bond length is 2.46 Å. Both Fe(2)-N(2) bond lengths are 1.99 Å. Both Fe(2)-N(3) bond lengths are 1.96 Å. In the third Fe site, Fe(3) is bonded to one C(1), one N(2), two equivalent N(1), and two equivalent N(4) atoms to form FeCN5 octahedra that share corners with four equivalent Fe(4)N5 trigonal bipyramids, edges with two equivalent Fe(3)CN5 octahedra, edges with two equivalent Fe(1)N4 tetrahedra,  an edgeedge with one Fe(4)N5 trigonal bipyramid, and  a faceface with one Fe(4)N5 trigonal bipyramid. The Fe(3)-C(1) bond length is 1.90 Å. The Fe(3)-N(2) bond length is 2.22 Å. Both Fe(3)-N(1) bond lengths are 2.05 Å. Both Fe(3)-N(4) bond lengths are 1.98 Å. In the fourth Fe site, Fe(4) is bonded to one N(2), two equivalent N(1), and two equivalent N(4) atoms to form distorted FeN5 trigonal bipyramids that share corners with four equivalent Fe(3)CN5 octahedra, corners with four equivalent Fe(1)N4 tetrahedra,  an edgeedge with one Fe(3)CN5 octahedra, edges with two equivalent Fe(4)N5 trigonal bipyramids, and  a faceface with one Fe(3)CN5 octahedra. The corner-sharing octahedral tilt angles range from 4-51°. The Fe(4)-N(2) bond length is 1.96 Å. Both Fe(4)-N(1) bond lengths are 1.91 Å. Both Fe(4)-N(4) bond lengths are 2.20 Å. C(1) is bonded in a trigonal planar geometry to one Fe(3), one N(3), and one N(4) atom. The C(1)-N(3) bond length is 1.35 Å. The C(1)-N(4) bond length is 1.37 Å. There are four inequivalent N sites. In the first N site, N(4) is bonded in a 5-coordinate geometry to two equivalent Fe(3), two equivalent Fe(4), and one C(1) atom. In the second N site, N(1) is bonded to one Fe(1), one Fe(2), two equivalent Fe(3), and two equivalent Fe(4) atoms to form distorted edge-sharing NFe6 octahedra. In the third N site, N(2) is bonded in a 6-coordinate geometry to one Fe(3), one Fe(4), two equivalent Fe(1), and two equivalent Fe(2) atoms. In the fourth N site, N(3) is bonded in a rectangular see-saw-like geometry to one Fe(1), two equivalent Fe(2), and one C(1) atom.