CaFeO2Cl crystallizes in the monoclinic C2/m space group. Ca(1) is bonded in a 7-coordinate geometry to one O(1), two equivalent O(2), and four equivalent Cl(1) atoms. Fe(1) is bonded to two equivalent O(2) and three equivalent O(1) atoms to form a mixture of edge and corner-sharing FeO5 trigonal bipyramids. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1) and three equivalent Fe(1) atoms to form distorted OCaFe3 trigonal pyramids that share corners with four equivalent Cl(1)Ca4 tetrahedra, corners with two equivalent O(1)CaFe3 trigonal pyramids, corners with four equivalent O(2)Ca2Fe2 trigonal pyramids, edges with two equivalent O(2)Ca2Fe2 trigonal pyramids, and edges with two equivalent O(1)CaFe3 trigonal pyramids. In the second O site, O(2) is bonded to two equivalent Ca(1) and two equivalent Fe(1) atoms to form OCa2Fe2 trigonal pyramids that share corners with six equivalent Cl(1)Ca4 tetrahedra, corners with two equivalent O(2)Ca2Fe2 trigonal pyramids, corners with four equivalent O(1)CaFe3 trigonal pyramids,  an edgeedge with one Cl(1)Ca4 tetrahedra,  an edgeedge with one O(2)Ca2Fe2 trigonal pyramid, and edges with two equivalent O(1)CaFe3 trigonal pyramids. Cl(1) is bonded to four equivalent Ca(1) atoms to form ClCa4 tetrahedra that share corners with six equivalent Cl(1)Ca4 tetrahedra, corners with four equivalent O(1)CaFe3 trigonal pyramids, corners with six equivalent O(2)Ca2Fe2 trigonal pyramids, edges with three equivalent Cl(1)Ca4 tetrahedra, and  an edgeedge with one O(2)Ca2Fe2 trigonal pyramid.
CaFeO2Cl crystallizes in the monoclinic C2/m space group. Ca(1) is bonded in a 7-coordinate geometry to one O(1), two equivalent O(2), and four equivalent Cl(1) atoms. The Ca(1)-O(1) bond length is 2.39 Å. Both Ca(1)-O(2) bond lengths are 2.31 Å. There are a spread of Ca(1)-Cl(1) bond distances ranging from 2.84-3.05 Å. Fe(1) is bonded to two equivalent O(2) and three equivalent O(1) atoms to form a mixture of edge and corner-sharing FeO5 trigonal bipyramids. There is one shorter (1.92 Å) and one longer (2.04 Å) Fe(1)-O(2) bond length. There is one shorter (1.98 Å) and two longer (2.03 Å) Fe(1)-O(1) bond lengths. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1) and three equivalent Fe(1) atoms to form distorted OCaFe3 trigonal pyramids that share corners with four equivalent Cl(1)Ca4 tetrahedra, corners with two equivalent O(1)CaFe3 trigonal pyramids, corners with four equivalent O(2)Ca2Fe2 trigonal pyramids, edges with two equivalent O(2)Ca2Fe2 trigonal pyramids, and edges with two equivalent O(1)CaFe3 trigonal pyramids. In the second O site, O(2) is bonded to two equivalent Ca(1) and two equivalent Fe(1) atoms to form OCa2Fe2 trigonal pyramids that share corners with six equivalent Cl(1)Ca4 tetrahedra, corners with two equivalent O(2)Ca2Fe2 trigonal pyramids, corners with four equivalent O(1)CaFe3 trigonal pyramids,  an edgeedge with one Cl(1)Ca4 tetrahedra,  an edgeedge with one O(2)Ca2Fe2 trigonal pyramid, and edges with two equivalent O(1)CaFe3 trigonal pyramids. Cl(1) is bonded to four equivalent Ca(1) atoms to form ClCa4 tetrahedra that share corners with six equivalent Cl(1)Ca4 tetrahedra, corners with four equivalent O(1)CaFe3 trigonal pyramids, corners with six equivalent O(2)Ca2Fe2 trigonal pyramids, edges with three equivalent Cl(1)Ca4 tetrahedra, and  an edgeedge with one O(2)Ca2Fe2 trigonal pyramid.