CaFe4O6 crystallizes in the orthorhombic Cmcm space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(3), two equivalent O(4), and four equivalent O(2) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), two equivalent O(1), and three equivalent O(3) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 0-8°. In the second Fe site, Fe(2) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 0-50°. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Fe(2) and four equivalent Fe(1) atoms to form OFe6 octahedra that share corners with four equivalent O(3)CaFe5 octahedra, corners with two equivalent O(4)Ca2Fe2 tetrahedra, edges with two equivalent O(1)Fe6 octahedra, edges with six equivalent O(3)CaFe5 octahedra, and edges with four equivalent O(2)Ca2Fe3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 4°. In the second O site, O(2) is bonded to two equivalent Ca(1), one Fe(1), and two equivalent Fe(2) atoms to form distorted OCa2Fe3 trigonal bipyramids that share corners with five equivalent O(3)CaFe5 octahedra, corners with four equivalent O(4)Ca2Fe2 tetrahedra, corners with two equivalent O(2)Ca2Fe3 trigonal bipyramids, edges with two equivalent O(1)Fe6 octahedra, edges with three equivalent O(3)CaFe5 octahedra,  an edgeedge with one O(4)Ca2Fe2 tetrahedra, and edges with three equivalent O(2)Ca2Fe3 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 8-41°. In the third O site, O(3) is bonded to one Ca(1), two equivalent Fe(2), and three equivalent Fe(1) atoms to form distorted OCaFe5 octahedra that share  a cornercorner with one O(3)CaFe5 octahedra, corners with two equivalent O(1)Fe6 octahedra, corners with five equivalent O(2)Ca2Fe3 trigonal bipyramids, edges with three equivalent O(1)Fe6 octahedra, edges with four equivalent O(3)CaFe5 octahedra, edges with two equivalent O(4)Ca2Fe2 tetrahedra, and edges with three equivalent O(2)Ca2Fe3 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 4-56°. In the fourth O site, O(4) is bonded to two equivalent Ca(1) and two equivalent Fe(2) atoms to form distorted OCa2Fe2 tetrahedra that share corners with two equivalent O(1)Fe6 octahedra, corners with two equivalent O(4)Ca2Fe2 tetrahedra, corners with eight equivalent O(2)Ca2Fe3 trigonal bipyramids, edges with four equivalent O(3)CaFe5 octahedra, and edges with two equivalent O(2)Ca2Fe3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 1°.
CaFe4O6 crystallizes in the orthorhombic Cmcm space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(3), two equivalent O(4), and four equivalent O(2) atoms. Both Ca(1)-O(3) bond lengths are 2.87 Å. Both Ca(1)-O(4) bond lengths are 2.31 Å. All Ca(1)-O(2) bond lengths are 2.43 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), two equivalent O(1), and three equivalent O(3) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 0-8°. The Fe(1)-O(2) bond length is 2.04 Å. Both Fe(1)-O(1) bond lengths are 2.17 Å. There is one shorter (2.14 Å) and two longer (2.27 Å) Fe(1)-O(3) bond lengths. In the second Fe site, Fe(2) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 0-50°. The Fe(2)-O(1) bond length is 2.28 Å. The Fe(2)-O(4) bond length is 1.97 Å. Both Fe(2)-O(2) bond lengths are 2.07 Å. Both Fe(2)-O(3) bond lengths are 2.09 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Fe(2) and four equivalent Fe(1) atoms to form OFe6 octahedra that share corners with four equivalent O(3)CaFe5 octahedra, corners with two equivalent O(4)Ca2Fe2 tetrahedra, edges with two equivalent O(1)Fe6 octahedra, edges with six equivalent O(3)CaFe5 octahedra, and edges with four equivalent O(2)Ca2Fe3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 4°. In the second O site, O(2) is bonded to two equivalent Ca(1), one Fe(1), and two equivalent Fe(2) atoms to form distorted OCa2Fe3 trigonal bipyramids that share corners with five equivalent O(3)CaFe5 octahedra, corners with four equivalent O(4)Ca2Fe2 tetrahedra, corners with two equivalent O(2)Ca2Fe3 trigonal bipyramids, edges with two equivalent O(1)Fe6 octahedra, edges with three equivalent O(3)CaFe5 octahedra,  an edgeedge with one O(4)Ca2Fe2 tetrahedra, and edges with three equivalent O(2)Ca2Fe3 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 8-41°. In the third O site, O(3) is bonded to one Ca(1), two equivalent Fe(2), and three equivalent Fe(1) atoms to form distorted OCaFe5 octahedra that share  a cornercorner with one O(3)CaFe5 octahedra, corners with two equivalent O(1)Fe6 octahedra, corners with five equivalent O(2)Ca2Fe3 trigonal bipyramids, edges with three equivalent O(1)Fe6 octahedra, edges with four equivalent O(3)CaFe5 octahedra, edges with two equivalent O(4)Ca2Fe2 tetrahedra, and edges with three equivalent O(2)Ca2Fe3 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 4-56°. In the fourth O site, O(4) is bonded to two equivalent Ca(1) and two equivalent Fe(2) atoms to form distorted OCa2Fe2 tetrahedra that share corners with two equivalent O(1)Fe6 octahedra, corners with two equivalent O(4)Ca2Fe2 tetrahedra, corners with eight equivalent O(2)Ca2Fe3 trigonal bipyramids, edges with four equivalent O(3)CaFe5 octahedra, and edges with two equivalent O(2)Ca2Fe3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 1°.