Ca(Fe2O3)4 crystallizes in the monoclinic P2 space group. Ca(1) is bonded in a distorted trigonal planar geometry to one O(6), two equivalent O(1), and two equivalent O(2) atoms. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(3), one O(5), one O(7), and two equivalent O(1) atoms to form a mixture of corner, face, and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 42-58°. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(8) atom to form a mixture of distorted corner, face, and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 39-62°. In the third Fe site, Fe(3) is bonded to one O(1), one O(4), one O(5), one O(7), and two equivalent O(3) atoms to form a mixture of distorted corner, face, and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 39-58°. In the fourth Fe site, Fe(4) is bonded to one O(2), one O(3), one O(6), one O(8), and two equivalent O(4) atoms to form a mixture of distorted corner, face, and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 25-58°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Ca(1), one Fe(2), one Fe(3), and two equivalent Fe(1) atoms. In the second O site, O(2) is bonded to one Ca(1), one Fe(1), one Fe(2), and one Fe(4) atom to form OCaFe3 tetrahedra that share  a cornercorner with one O(2)CaFe3 tetrahedra,  a cornercorner with one O(3)Fe5 trigonal bipyramid,  a cornercorner with one O(4)Fe4 trigonal pyramid, corners with two equivalent O(8)Fe4 trigonal pyramids,  an edgeedge with one O(5)Fe6 pentagonal pyramid,  an edgeedge with one O(3)Fe5 trigonal bipyramid, and  an edgeedge with one O(4)Fe4 trigonal pyramid. In the third O site, O(3) is bonded to one Fe(1), one Fe(2), one Fe(4), and two equivalent Fe(3) atoms to form distorted OFe5 trigonal bipyramids that share  a cornercorner with one O(2)CaFe3 tetrahedra, corners with three equivalent O(4)Fe4 trigonal pyramids, edges with two equivalent O(5)Fe6 pentagonal pyramids,  an edgeedge with one O(2)CaFe3 tetrahedra,  an edgeedge with one O(3)Fe5 trigonal bipyramid,  an edgeedge with one O(4)Fe4 trigonal pyramid, and  an edgeedge with one O(8)Fe4 trigonal pyramid. In the fourth O site, O(4) is bonded to one Fe(2), one Fe(3), and two equivalent Fe(4) atoms to form distorted OFe4 trigonal pyramids that share  a cornercorner with one O(2)CaFe3 tetrahedra, corners with three equivalent O(3)Fe5 trigonal bipyramids,  a cornercorner with one O(8)Fe4 trigonal pyramid,  an edgeedge with one O(5)Fe6 pentagonal pyramid,  an edgeedge with one O(2)CaFe3 tetrahedra,  an edgeedge with one O(3)Fe5 trigonal bipyramid,  an edgeedge with one O(4)Fe4 trigonal pyramid, and  an edgeedge with one O(8)Fe4 trigonal pyramid. In the fifth O site, O(5) is bonded to two equivalent Fe(1), two equivalent Fe(2), and two equivalent Fe(3) atoms to form distorted OFe6 pentagonal pyramids that share corners with two equivalent O(8)Fe4 trigonal pyramids, edges with two equivalent O(2)CaFe3 tetrahedra, edges with four equivalent O(3)Fe5 trigonal bipyramids, and edges with two equivalent O(4)Fe4 trigonal pyramids. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Ca(1) and two equivalent Fe(4) atoms. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Fe(1) and two equivalent Fe(3) atoms. In the eighth O site, O(8) is bonded to two equivalent Fe(2) and two equivalent Fe(4) atoms to form distorted OFe4 trigonal pyramids that share corners with two equivalent O(5)Fe6 pentagonal pyramids, corners with four equivalent O(2)CaFe3 tetrahedra, corners with two equivalent O(4)Fe4 trigonal pyramids, edges with two equivalent O(3)Fe5 trigonal bipyramids, and edges with two equivalent O(4)Fe4 trigonal pyramids.
Ca(Fe2O3)4 crystallizes in the monoclinic P2 space group. Ca(1) is bonded in a distorted trigonal planar geometry to one O(6), two equivalent O(1), and two equivalent O(2) atoms. The Ca(1)-O(6) bond length is 2.16 Å. Both Ca(1)-O(1) bond lengths are 2.93 Å. Both Ca(1)-O(2) bond lengths are 2.13 Å. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(3), one O(5), one O(7), and two equivalent O(1) atoms to form a mixture of corner, face, and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 42-58°. The Fe(1)-O(2) bond length is 1.97 Å. The Fe(1)-O(3) bond length is 2.29 Å. The Fe(1)-O(5) bond length is 2.24 Å. The Fe(1)-O(7) bond length is 2.18 Å. There is one shorter (2.06 Å) and one longer (2.30 Å) Fe(1)-O(1) bond length. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(8) atom to form a mixture of distorted corner, face, and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 39-62°. The Fe(2)-O(1) bond length is 1.99 Å. The Fe(2)-O(2) bond length is 1.98 Å. The Fe(2)-O(3) bond length is 2.16 Å. The Fe(2)-O(4) bond length is 2.01 Å. The Fe(2)-O(5) bond length is 2.31 Å. The Fe(2)-O(8) bond length is 2.04 Å. In the third Fe site, Fe(3) is bonded to one O(1), one O(4), one O(5), one O(7), and two equivalent O(3) atoms to form a mixture of distorted corner, face, and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 39-58°. The Fe(3)-O(1) bond length is 2.03 Å. The Fe(3)-O(4) bond length is 2.05 Å. The Fe(3)-O(5) bond length is 2.20 Å. The Fe(3)-O(7) bond length is 1.99 Å. There is one shorter (2.22 Å) and one longer (2.24 Å) Fe(3)-O(3) bond length. In the fourth Fe site, Fe(4) is bonded to one O(2), one O(3), one O(6), one O(8), and two equivalent O(4) atoms to form a mixture of distorted corner, face, and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 25-58°. The Fe(4)-O(2) bond length is 1.94 Å. The Fe(4)-O(3) bond length is 2.09 Å. The Fe(4)-O(6) bond length is 1.93 Å. The Fe(4)-O(8) bond length is 2.18 Å. There is one shorter (2.13 Å) and one longer (2.24 Å) Fe(4)-O(4) bond length. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Ca(1), one Fe(2), one Fe(3), and two equivalent Fe(1) atoms. In the second O site, O(2) is bonded to one Ca(1), one Fe(1), one Fe(2), and one Fe(4) atom to form OCaFe3 tetrahedra that share  a cornercorner with one O(2)CaFe3 tetrahedra,  a cornercorner with one O(3)Fe5 trigonal bipyramid,  a cornercorner with one O(4)Fe4 trigonal pyramid, corners with two equivalent O(8)Fe4 trigonal pyramids,  an edgeedge with one O(5)Fe6 pentagonal pyramid,  an edgeedge with one O(3)Fe5 trigonal bipyramid, and  an edgeedge with one O(4)Fe4 trigonal pyramid. In the third O site, O(3) is bonded to one Fe(1), one Fe(2), one Fe(4), and two equivalent Fe(3) atoms to form distorted OFe5 trigonal bipyramids that share  a cornercorner with one O(2)CaFe3 tetrahedra, corners with three equivalent O(4)Fe4 trigonal pyramids, edges with two equivalent O(5)Fe6 pentagonal pyramids,  an edgeedge with one O(2)CaFe3 tetrahedra,  an edgeedge with one O(3)Fe5 trigonal bipyramid,  an edgeedge with one O(4)Fe4 trigonal pyramid, and  an edgeedge with one O(8)Fe4 trigonal pyramid. In the fourth O site, O(4) is bonded to one Fe(2), one Fe(3), and two equivalent Fe(4) atoms to form distorted OFe4 trigonal pyramids that share  a cornercorner with one O(2)CaFe3 tetrahedra, corners with three equivalent O(3)Fe5 trigonal bipyramids,  a cornercorner with one O(8)Fe4 trigonal pyramid,  an edgeedge with one O(5)Fe6 pentagonal pyramid,  an edgeedge with one O(2)CaFe3 tetrahedra,  an edgeedge with one O(3)Fe5 trigonal bipyramid,  an edgeedge with one O(4)Fe4 trigonal pyramid, and  an edgeedge with one O(8)Fe4 trigonal pyramid. In the fifth O site, O(5) is bonded to two equivalent Fe(1), two equivalent Fe(2), and two equivalent Fe(3) atoms to form distorted OFe6 pentagonal pyramids that share corners with two equivalent O(8)Fe4 trigonal pyramids, edges with two equivalent O(2)CaFe3 tetrahedra, edges with four equivalent O(3)Fe5 trigonal bipyramids, and edges with two equivalent O(4)Fe4 trigonal pyramids. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Ca(1) and two equivalent Fe(4) atoms. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Fe(1) and two equivalent Fe(3) atoms. In the eighth O site, O(8) is bonded to two equivalent Fe(2) and two equivalent Fe(4) atoms to form distorted OFe4 trigonal pyramids that share corners with two equivalent O(5)Fe6 pentagonal pyramids, corners with four equivalent O(2)CaFe3 tetrahedra, corners with two equivalent O(4)Fe4 trigonal pyramids, edges with two equivalent O(3)Fe5 trigonal bipyramids, and edges with two equivalent O(4)Fe4 trigonal pyramids.