The material described by Li4Cr3AlO8 is alpha Po-derived structured and crystallizes in the monoclinic C2 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form LiO6 octahedra that share corners with three equivalent Cr(1)O6 octahedra, corners with three equivalent Cr(3)O6 octahedra,  an edgeedge with one Cr(1)O6 octahedra,  an edgeedge with one Cr(3)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Cr(2)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, and edges with four equivalent Li(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-8°. In the second Li site, Li(2) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form LiO6 octahedra that share corners with three equivalent Cr(2)O6 octahedra, corners with three equivalent Al(1)O6 octahedra,  an edgeedge with one Cr(2)O6 octahedra,  an edgeedge with one Al(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Cr(3)O6 octahedra, and edges with four equivalent Li(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-8°. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form CrO6 octahedra that share corners with six equivalent Li(1)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Cr(2)O6 octahedra, edges with two equivalent Cr(3)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, and edges with four equivalent Li(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(2), two equivalent O(3), and two equivalent O(4) atoms to form CrO6 octahedra that share corners with six equivalent Li(2)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Cr(3)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, and edges with four equivalent Li(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-8°. In the third Cr site, Cr(3) 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(1)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Cr(2)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, and edges with four equivalent Li(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-8°. Al(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form AlO6 octahedra that share corners with six equivalent Li(2)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Cr(2)O6 octahedra, edges with two equivalent Cr(3)O6 octahedra, and edges with four equivalent Li(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-5°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Li(2), two equivalent Li(1), one Cr(1), one Cr(3), and one Al(1) atom to form OLi3AlCr2 octahedra that share corners with three equivalent O(1)Li3AlCr2 octahedra, corners with three equivalent O(2)Li3Cr3 octahedra,  an edgeedge with one O(1)Li3AlCr2 octahedra, edges with three equivalent O(2)Li3Cr3 octahedra, edges with four equivalent O(3)Li3AlCr2 octahedra, and edges with four equivalent O(4)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(1), one Cr(1), one Cr(2), and one Cr(3) atom to form OLi3Cr3 octahedra that share corners with three equivalent O(1)Li3AlCr2 octahedra, corners with three equivalent O(2)Li3Cr3 octahedra,  an edgeedge with one O(2)Li3Cr3 octahedra, edges with three equivalent O(1)Li3AlCr2 octahedra, edges with four equivalent O(3)Li3AlCr2 octahedra, and edges with four equivalent O(4)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), two equivalent Li(2), one Cr(2), one Cr(3), and one Al(1) atom to form OLi3AlCr2 octahedra that share corners with three equivalent O(3)Li3AlCr2 octahedra, corners with three equivalent O(4)Li3AlCr2 octahedra,  an edgeedge with one O(3)Li3AlCr2 octahedra, edges with three equivalent O(4)Li3AlCr2 octahedra, edges with four equivalent O(1)Li3AlCr2 octahedra, and edges with four equivalent O(2)Li3Cr3 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the fourth O site, O(4) is bonded to one Li(1), two equivalent Li(2), one Cr(1), one Cr(2), and one Al(1) atom to form OLi3AlCr2 octahedra that share corners with three equivalent O(3)Li3AlCr2 octahedra, corners with three equivalent O(4)Li3AlCr2 octahedra,  an edgeedge with one O(4)Li3AlCr2 octahedra, edges with three equivalent O(3)Li3AlCr2 octahedra, edges with four equivalent O(1)Li3AlCr2 octahedra, and edges with four equivalent O(2)Li3Cr3 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. is represented by the CIF file [CIF]
data_Li4AlCr3O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.078
_cell_length_b   5.916
_cell_length_c   5.852
_cell_angle_alpha   119.642
_cell_angle_beta   90.001
_cell_angle_gamma   73.416
_symmetry_Int_Tables_number   1
_cell_volume   144.290
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Li  Li0  1  0.000  1.000  1.000  1.0
  Li  Li1  1  1.000  0.000  0.500  1.0
  Li  Li2  1  0.499  0.001  0.250  1.0
  Li  Li3  1  0.501  0.999  0.749  1.0
  Al  Al4  1  0.000  0.500  0.501  1.0
  Cr  Cr5  1  0.500  0.500  0.251  1.0
  Cr  Cr6  1  0.000  0.500  0.002  1.0
  Cr  Cr7  1  0.500  0.500  0.746  1.0
  O  O8  1  0.755  0.278  0.388  1.0
  O  O9  1  0.245  0.722  0.610  1.0
  O  O10  1  0.259  0.728  0.113  1.0
  O  O11  1  0.741  0.272  0.885  1.0
  O  O12  1  0.234  0.280  0.632  1.0
  O  O13  1  0.235  0.279  0.150  1.0
  O  O14  1  0.766  0.720  0.852  1.0
  O  O15  1  0.765  0.721  0.371  1.0
[/CIF]
.
The material described by Li4Cr3AlO8 is alpha Po-derived structured and crystallizes in the monoclinic C2 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form LiO6 octahedra that share corners with three equivalent Cr(1)O6 octahedra, corners with three equivalent Cr(3)O6 octahedra,  an edgeedge with one Cr(1)O6 octahedra,  an edgeedge with one Cr(3)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Cr(2)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, and edges with four equivalent Li(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-8°. In the second Li site, Li(2) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form LiO6 octahedra that share corners with three equivalent Cr(2)O6 octahedra, corners with three equivalent Al(1)O6 octahedra,  an edgeedge with one Cr(2)O6 octahedra,  an edgeedge with one Al(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Cr(3)O6 octahedra, and edges with four equivalent Li(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-8°. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form CrO6 octahedra that share corners with six equivalent Li(1)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Cr(2)O6 octahedra, edges with two equivalent Cr(3)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, and edges with four equivalent Li(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(2), two equivalent O(3), and two equivalent O(4) atoms to form CrO6 octahedra that share corners with six equivalent Li(2)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Cr(3)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, and edges with four equivalent Li(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-8°. In the third Cr site, Cr(3) 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(1)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Cr(2)O6 octahedra, edges with two equivalent Al(1)O6 octahedra, and edges with four equivalent Li(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-8°. Al(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form AlO6 octahedra that share corners with six equivalent Li(2)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, edges with two equivalent Cr(2)O6 octahedra, edges with two equivalent Cr(3)O6 octahedra, and edges with four equivalent Li(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-5°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Li(2), two equivalent Li(1), one Cr(1), one Cr(3), and one Al(1) atom to form OLi3AlCr2 octahedra that share corners with three equivalent O(1)Li3AlCr2 octahedra, corners with three equivalent O(2)Li3Cr3 octahedra,  an edgeedge with one O(1)Li3AlCr2 octahedra, edges with three equivalent O(2)Li3Cr3 octahedra, edges with four equivalent O(3)Li3AlCr2 octahedra, and edges with four equivalent O(4)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(1), one Cr(1), one Cr(2), and one Cr(3) atom to form OLi3Cr3 octahedra that share corners with three equivalent O(1)Li3AlCr2 octahedra, corners with three equivalent O(2)Li3Cr3 octahedra,  an edgeedge with one O(2)Li3Cr3 octahedra, edges with three equivalent O(1)Li3AlCr2 octahedra, edges with four equivalent O(3)Li3AlCr2 octahedra, and edges with four equivalent O(4)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), two equivalent Li(2), one Cr(2), one Cr(3), and one Al(1) atom to form OLi3AlCr2 octahedra that share corners with three equivalent O(3)Li3AlCr2 octahedra, corners with three equivalent O(4)Li3AlCr2 octahedra,  an edgeedge with one O(3)Li3AlCr2 octahedra, edges with three equivalent O(4)Li3AlCr2 octahedra, edges with four equivalent O(1)Li3AlCr2 octahedra, and edges with four equivalent O(2)Li3Cr3 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the fourth O site, O(4) is bonded to one Li(1), two equivalent Li(2), one Cr(1), one Cr(2), and one Al(1) atom to form OLi3AlCr2 octahedra that share corners with three equivalent O(3)Li3AlCr2 octahedra, corners with three equivalent O(4)Li3AlCr2 octahedra,  an edgeedge with one O(4)Li3AlCr2 octahedra, edges with three equivalent O(3)Li3AlCr2 octahedra, edges with four equivalent O(1)Li3AlCr2 octahedra, and edges with four equivalent O(2)Li3Cr3 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. is represented by the CIF file [CIF]
data_Li4AlCr3O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.078
_cell_length_b   5.916
_cell_length_c   5.852
_cell_angle_alpha   119.642
_cell_angle_beta   90.001
_cell_angle_gamma   73.416
_symmetry_Int_Tables_number   1
_cell_volume   144.290
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Li  Li0  1  0.000  1.000  1.000  1.0
  Li  Li1  1  1.000  0.000  0.500  1.0
  Li  Li2  1  0.499  0.001  0.250  1.0
  Li  Li3  1  0.501  0.999  0.749  1.0
  Al  Al4  1  0.000  0.500  0.501  1.0
  Cr  Cr5  1  0.500  0.500  0.251  1.0
  Cr  Cr6  1  0.000  0.500  0.002  1.0
  Cr  Cr7  1  0.500  0.500  0.746  1.0
  O  O8  1  0.755  0.278  0.388  1.0
  O  O9  1  0.245  0.722  0.610  1.0
  O  O10  1  0.259  0.728  0.113  1.0
  O  O11  1  0.741  0.272  0.885  1.0
  O  O12  1  0.234  0.280  0.632  1.0
  O  O13  1  0.235  0.279  0.150  1.0
  O  O14  1  0.766  0.720  0.852  1.0
  O  O15  1  0.765  0.721  0.371  1.0
[/CIF]
.