Li4Cr3AlO8 is alpha Po-derived structured and crystallizes in the monoclinic P2/m space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form LiO6 octahedra that share corners with two equivalent Al(1)O6 octahedra, corners with four equivalent Cr(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, edges with four equivalent Li(3)O6 octahedra, and edges with four equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-8°. In the second Li site, Li(2) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form LiO6 octahedra that share corners with two equivalent Cr(1)O6 octahedra, corners with four equivalent Al(1)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with four equivalent Li(3)O6 octahedra, and edges with four equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-5°. In the third Li site, Li(3) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form LiO6 octahedra that share corners with six equivalent Cr(2)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Cr(2)O6 octahedra, and edges with two equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-8°. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form CrO6 octahedra that share corners with two equivalent Li(2)O6 octahedra, corners with four equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, edges with four equivalent Li(3)O6 octahedra, and edges with four equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-8°. In the second Cr site, Cr(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form CrO6 octahedra that share corners with six equivalent Li(3)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Cr(2)O6 octahedra, and edges with two equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-8°. Al(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form AlO6 octahedra that share corners with two equivalent Li(1)O6 octahedra, corners with four equivalent Li(2)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with four equivalent Li(3)O6 octahedra, and edges with four equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles are 4°. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), two equivalent Li(3), two equivalent Cr(2), and one Al(1) atom to form OLi3AlCr2 octahedra that share corners with two equivalent O(1)Li3AlCr2 octahedra, corners with four equivalent O(2)Li3Cr3 octahedra, edges with two equivalent O(1)Li3AlCr2 octahedra, edges with two equivalent O(2)Li3Cr3 octahedra, and edges with eight equivalent O(3)Li3AlCr2 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the second O site, O(2) is bonded to one Li(2), two equivalent Li(3), one Cr(1), and two equivalent Cr(2) atoms to form OLi3Cr3 octahedra that share corners with two equivalent O(2)Li3Cr3 octahedra, corners with four equivalent O(1)Li3AlCr2 octahedra, edges with two equivalent O(1)Li3AlCr2 octahedra, edges with two equivalent O(2)Li3Cr3 octahedra, and edges with eight equivalent O(3)Li3AlCr2 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Li(3), one Cr(1), one Cr(2), and one Al(1) atom to form OLi3AlCr2 octahedra that share corners with six equivalent O(3)Li3AlCr2 octahedra, edges with four equivalent O(1)Li3AlCr2 octahedra, edges with four equivalent O(3)Li3AlCr2 octahedra, and edges with four equivalent O(2)Li3Cr3 octahedra. The corner-sharing octahedral tilt angles range from 0-2°.
Li4Cr3AlO8 is alpha Po-derived structured and crystallizes in the monoclinic P2/m space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form LiO6 octahedra that share corners with two equivalent Al(1)O6 octahedra, corners with four equivalent Cr(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, edges with four equivalent Li(3)O6 octahedra, and edges with four equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-8°. Both Li(1)-O(1) bond lengths are 2.22 Å. All Li(1)-O(3) bond lengths are 2.14 Å. In the second Li site, Li(2) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form LiO6 octahedra that share corners with two equivalent Cr(1)O6 octahedra, corners with four equivalent Al(1)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with four equivalent Li(3)O6 octahedra, and edges with four equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-5°. Both Li(2)-O(2) bond lengths are 2.13 Å. All Li(2)-O(3) bond lengths are 2.22 Å. In the third Li site, Li(3) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form LiO6 octahedra that share corners with six equivalent Cr(2)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Cr(2)O6 octahedra, and edges with two equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-8°. Both Li(3)-O(1) bond lengths are 2.13 Å. Both Li(3)-O(2) bond lengths are 2.16 Å. Both Li(3)-O(3) bond lengths are 2.14 Å. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form CrO6 octahedra that share corners with two equivalent Li(2)O6 octahedra, corners with four equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, edges with four equivalent Li(3)O6 octahedra, and edges with four equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-8°. Both Cr(1)-O(2) bond lengths are 2.03 Å. All Cr(1)-O(3) bond lengths are 2.03 Å. In the second Cr site, Cr(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form CrO6 octahedra that share corners with six equivalent Li(3)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Cr(2)O6 octahedra, and edges with two equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-8°. Both Cr(2)-O(1) bond lengths are 2.02 Å. Both Cr(2)-O(2) bond lengths are 2.03 Å. Both Cr(2)-O(3) bond lengths are 2.03 Å. Al(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form AlO6 octahedra that share corners with two equivalent Li(1)O6 octahedra, corners with four equivalent Li(2)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with four equivalent Li(3)O6 octahedra, and edges with four equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles are 4°. Both Al(1)-O(1) bond lengths are 1.94 Å. All Al(1)-O(3) bond lengths are 1.95 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), two equivalent Li(3), two equivalent Cr(2), and one Al(1) atom to form OLi3AlCr2 octahedra that share corners with two equivalent O(1)Li3AlCr2 octahedra, corners with four equivalent O(2)Li3Cr3 octahedra, edges with two equivalent O(1)Li3AlCr2 octahedra, edges with two equivalent O(2)Li3Cr3 octahedra, and edges with eight equivalent O(3)Li3AlCr2 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the second O site, O(2) is bonded to one Li(2), two equivalent Li(3), one Cr(1), and two equivalent Cr(2) atoms to form OLi3Cr3 octahedra that share corners with two equivalent O(2)Li3Cr3 octahedra, corners with four equivalent O(1)Li3AlCr2 octahedra, edges with two equivalent O(1)Li3AlCr2 octahedra, edges with two equivalent O(2)Li3Cr3 octahedra, and edges with eight equivalent O(3)Li3AlCr2 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Li(3), one Cr(1), one Cr(2), and one Al(1) atom to form OLi3AlCr2 octahedra that share corners with six equivalent O(3)Li3AlCr2 octahedra, edges with four equivalent O(1)Li3AlCr2 octahedra, edges with four equivalent O(3)Li3AlCr2 octahedra, and edges with four equivalent O(2)Li3Cr3 octahedra. The corner-sharing octahedral tilt angles range from 0-2°.