Li6Fe5CuO12 is Corundum-derived structured and crystallizes in the monoclinic C2/m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a rectangular see-saw-like geometry to one O(2), one O(4), and two equivalent O(3) atoms. In the second Li site, Li(2) is bonded in a rectangular see-saw-like geometry to one O(1), one O(4), and two equivalent O(3) atoms. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form edge-sharing FeO6 octahedra. In the second Fe site, Fe(2) is bonded to two equivalent O(4) and four equivalent O(3) atoms to form FeO6 octahedra that share edges with three equivalent Fe(2)O6 octahedra and edges with three equivalent Cu(1)O6 octahedra. In the third Fe site, Fe(3) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form edge-sharing FeO6 octahedra. Cu(1) is bonded to two equivalent O(4) and four equivalent O(3) atoms to form CuO6 octahedra that share edges with six equivalent Fe(2)O6 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Li(2), one Fe(1), and two equivalent Fe(3) atoms to form OLiFe3 trigonal pyramids that share  a cornercorner with one O(4)Li3Fe2Cu octahedra, corners with two equivalent O(3)Li3Fe2Cu octahedra,  a cornercorner with one O(1)LiFe3 trigonal pyramid, corners with eight equivalent O(2)LiFe3 trigonal pyramids,  an edgeedge with one O(1)LiFe3 trigonal pyramid, and edges with two equivalent O(2)LiFe3 trigonal pyramids. The corner-sharing octahedral tilt angles range from 35-69°. In the second O site, O(2) is bonded to one Li(1), one Fe(1), and two equivalent Fe(3) atoms to form OLiFe3 trigonal pyramids that share  a cornercorner with one O(4)Li3Fe2Cu octahedra, corners with two equivalent O(3)Li3Fe2Cu octahedra, corners with four equivalent O(1)LiFe3 trigonal pyramids, corners with five equivalent O(2)LiFe3 trigonal pyramids,  an edgeedge with one O(1)LiFe3 trigonal pyramid, and edges with two equivalent O(2)LiFe3 trigonal pyramids. The corner-sharing octahedral tilt angles range from 33-72°. In the third O site, O(3) is bonded to one Li(2), two equivalent Li(1), two equivalent Fe(2), and one Cu(1) atom to form OLi3Fe2Cu octahedra that share  a cornercorner with one O(4)Li3Fe2Cu octahedra, corners with two equivalent O(3)Li3Fe2Cu octahedra,  a cornercorner with one O(1)LiFe3 trigonal pyramid, corners with two equivalent O(2)LiFe3 trigonal pyramids, edges with four equivalent O(4)Li3Fe2Cu octahedra, and edges with five equivalent O(3)Li3Fe2Cu octahedra. The corner-sharing octahedral tilt angles range from 0-5°. In the fourth O site, O(4) is bonded to one Li(2), two equivalent Li(1), two equivalent Fe(2), and one Cu(1) atom to form OLi3Fe2Cu octahedra that share  a cornercorner with one O(4)Li3Fe2Cu octahedra, corners with two equivalent O(3)Li3Fe2Cu octahedra,  a cornercorner with one O(1)LiFe3 trigonal pyramid, corners with two equivalent O(2)LiFe3 trigonal pyramids,  an edgeedge with one O(4)Li3Fe2Cu octahedra, and edges with eight equivalent O(3)Li3Fe2Cu octahedra. The corner-sharing octahedral tilt angles range from 0-5°.
Li6Fe5CuO12 is Corundum-derived structured and crystallizes in the monoclinic C2/m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a rectangular see-saw-like geometry to one O(2), one O(4), and two equivalent O(3) atoms. The Li(1)-O(2) bond length is 1.92 Å. The Li(1)-O(4) bond length is 2.03 Å. There is one shorter (2.09 Å) and one longer (2.10 Å) Li(1)-O(3) bond length. In the second Li site, Li(2) is bonded in a rectangular see-saw-like geometry to one O(1), one O(4), and two equivalent O(3) atoms. The Li(2)-O(1) bond length is 1.93 Å. The Li(2)-O(4) bond length is 1.99 Å. Both Li(2)-O(3) bond lengths are 2.03 Å. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form edge-sharing FeO6 octahedra. Both Fe(1)-O(1) bond lengths are 2.06 Å. All Fe(1)-O(2) bond lengths are 2.03 Å. In the second Fe site, Fe(2) is bonded to two equivalent O(4) and four equivalent O(3) atoms to form FeO6 octahedra that share edges with three equivalent Fe(2)O6 octahedra and edges with three equivalent Cu(1)O6 octahedra. Both Fe(2)-O(4) bond lengths are 2.03 Å. There are two shorter (2.05 Å) and two longer (2.09 Å) Fe(2)-O(3) bond lengths. In the third Fe site, Fe(3) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form edge-sharing FeO6 octahedra. Both Fe(3)-O(1) bond lengths are 2.01 Å. There are two shorter (1.96 Å) and two longer (2.04 Å) Fe(3)-O(2) bond lengths. Cu(1) is bonded to two equivalent O(4) and four equivalent O(3) atoms to form CuO6 octahedra that share edges with six equivalent Fe(2)O6 octahedra. Both Cu(1)-O(4) bond lengths are 2.25 Å. All Cu(1)-O(3) bond lengths are 2.06 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Li(2), one Fe(1), and two equivalent Fe(3) atoms to form OLiFe3 trigonal pyramids that share  a cornercorner with one O(4)Li3Fe2Cu octahedra, corners with two equivalent O(3)Li3Fe2Cu octahedra,  a cornercorner with one O(1)LiFe3 trigonal pyramid, corners with eight equivalent O(2)LiFe3 trigonal pyramids,  an edgeedge with one O(1)LiFe3 trigonal pyramid, and edges with two equivalent O(2)LiFe3 trigonal pyramids. The corner-sharing octahedral tilt angles range from 35-69°. In the second O site, O(2) is bonded to one Li(1), one Fe(1), and two equivalent Fe(3) atoms to form OLiFe3 trigonal pyramids that share  a cornercorner with one O(4)Li3Fe2Cu octahedra, corners with two equivalent O(3)Li3Fe2Cu octahedra, corners with four equivalent O(1)LiFe3 trigonal pyramids, corners with five equivalent O(2)LiFe3 trigonal pyramids,  an edgeedge with one O(1)LiFe3 trigonal pyramid, and edges with two equivalent O(2)LiFe3 trigonal pyramids. The corner-sharing octahedral tilt angles range from 33-72°. In the third O site, O(3) is bonded to one Li(2), two equivalent Li(1), two equivalent Fe(2), and one Cu(1) atom to form OLi3Fe2Cu octahedra that share  a cornercorner with one O(4)Li3Fe2Cu octahedra, corners with two equivalent O(3)Li3Fe2Cu octahedra,  a cornercorner with one O(1)LiFe3 trigonal pyramid, corners with two equivalent O(2)LiFe3 trigonal pyramids, edges with four equivalent O(4)Li3Fe2Cu octahedra, and edges with five equivalent O(3)Li3Fe2Cu octahedra. The corner-sharing octahedral tilt angles range from 0-5°. In the fourth O site, O(4) is bonded to one Li(2), two equivalent Li(1), two equivalent Fe(2), and one Cu(1) atom to form OLi3Fe2Cu octahedra that share  a cornercorner with one O(4)Li3Fe2Cu octahedra, corners with two equivalent O(3)Li3Fe2Cu octahedra,  a cornercorner with one O(1)LiFe3 trigonal pyramid, corners with two equivalent O(2)LiFe3 trigonal pyramids,  an edgeedge with one O(4)Li3Fe2Cu octahedra, and edges with eight equivalent O(3)Li3Fe2Cu octahedra. The corner-sharing octahedral tilt angles range from 0-5°.