Li4Cr5FeO12 crystallizes in the monoclinic C2/m space group. Li(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent O(1) and two equivalent O(2) atoms. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form edge-sharing CrO6 octahedra. In the second Cr site, Cr(2) is bonded to two equivalent O(4) and four equivalent O(1) atoms to form CrO6 octahedra that share edges with three equivalent Cr(2)O6 octahedra and edges with three equivalent Fe(1)O6 octahedra. In the third Cr site, Cr(3) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form edge-sharing CrO6 octahedra. Fe(1) is bonded to two equivalent O(4) and four equivalent O(1) atoms to form FeO6 octahedra that share edges with six equivalent Cr(2)O6 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Li(1), two equivalent Cr(2), and one Fe(1) atom to form OLi2Cr2Fe trigonal bipyramids that share corners with two equivalent O(2)Li2Cr3 trigonal bipyramids, corners with three equivalent O(1)Li2Cr2Fe trigonal bipyramids,  an edgeedge with one O(2)Li2Cr3 trigonal bipyramid, and edges with four equivalent O(1)Li2Cr2Fe trigonal bipyramids. In the second O site, O(2) is bonded to two equivalent Li(1), one Cr(3), and two equivalent Cr(1) atoms to form OLi2Cr3 trigonal bipyramids that share corners with two equivalent O(1)Li2Cr2Fe trigonal bipyramids, corners with three equivalent O(2)Li2Cr3 trigonal bipyramids,  an edgeedge with one O(1)Li2Cr2Fe trigonal bipyramid, and edges with four equivalent O(2)Li2Cr3 trigonal bipyramids. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Cr(3) and two equivalent Cr(1) atoms. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to two equivalent Cr(2) and one Fe(1) atom.
Li4Cr5FeO12 crystallizes in the monoclinic C2/m space group. Li(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent O(1) and two equivalent O(2) atoms. There is one shorter (2.01 Å) and one longer (2.09 Å) Li(1)-O(1) bond length. There is one shorter (2.03 Å) and one longer (2.12 Å) Li(1)-O(2) bond length. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form edge-sharing CrO6 octahedra. Both Cr(1)-O(3) bond lengths are 1.96 Å. There are two shorter (1.99 Å) and two longer (2.03 Å) Cr(1)-O(2) bond lengths. In the second Cr site, Cr(2) is bonded to two equivalent O(4) and four equivalent O(1) atoms to form CrO6 octahedra that share edges with three equivalent Cr(2)O6 octahedra and edges with three equivalent Fe(1)O6 octahedra. Both Cr(2)-O(4) bond lengths are 1.99 Å. There are two shorter (1.99 Å) and two longer (2.04 Å) Cr(2)-O(1) bond lengths. In the third Cr site, Cr(3) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form edge-sharing CrO6 octahedra. Both Cr(3)-O(3) bond lengths are 1.94 Å. All Cr(3)-O(2) bond lengths are 2.05 Å. Fe(1) is bonded to two equivalent O(4) and four equivalent O(1) atoms to form FeO6 octahedra that share edges with six equivalent Cr(2)O6 octahedra. Both Fe(1)-O(4) bond lengths are 1.93 Å. All Fe(1)-O(1) bond lengths are 2.07 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Li(1), two equivalent Cr(2), and one Fe(1) atom to form OLi2Cr2Fe trigonal bipyramids that share corners with two equivalent O(2)Li2Cr3 trigonal bipyramids, corners with three equivalent O(1)Li2Cr2Fe trigonal bipyramids,  an edgeedge with one O(2)Li2Cr3 trigonal bipyramid, and edges with four equivalent O(1)Li2Cr2Fe trigonal bipyramids. In the second O site, O(2) is bonded to two equivalent Li(1), one Cr(3), and two equivalent Cr(1) atoms to form OLi2Cr3 trigonal bipyramids that share corners with two equivalent O(1)Li2Cr2Fe trigonal bipyramids, corners with three equivalent O(2)Li2Cr3 trigonal bipyramids,  an edgeedge with one O(1)Li2Cr2Fe trigonal bipyramid, and edges with four equivalent O(2)Li2Cr3 trigonal bipyramids. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Cr(3) and two equivalent Cr(1) atoms. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to two equivalent Cr(2) and one Fe(1) atom.