The material described by Na2Li2CoO4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted NaO6 octahedra that share corners with two equivalent Co(1)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, edges with two equivalent Na(1)O6 octahedra,  an edgeedge with one Li(2)O4 tetrahedra, and edges with two equivalent Co(1)O4 tetrahedra. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), one O(3), and one O(4) atom. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form distorted LiO4 tetrahedra that share corners with four equivalent Na(1)O6 octahedra, corners with two equivalent Co(1)O4 tetrahedra,  an edgeedge with one Na(1)O6 octahedra, and  an edgeedge with one Co(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 27-38°. Co(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form CoO4 tetrahedra that share corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Li(2)O4 tetrahedra, edges with two equivalent Na(1)O6 octahedra, and  an edgeedge with one Li(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 40-55°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Na(1), two equivalent Na(2), one Li(1), one Li(2), and one Co(1) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(1), two equivalent Na(2), one Li(1), one Li(2), and one Co(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Na(2), two equivalent Na(1), one Li(1), one Li(2), and one Co(1) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Na(2), two equivalent Na(1), one Li(1), one Li(2), and one Co(1) atom. is represented by the CIF card [CIF]
data_Na2Li2CoO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.392
_cell_length_b   6.497
_cell_length_c   10.261
_cell_angle_alpha   51.149
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   435.692
_cell_formula_units_Z   4
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
  Na  Na0  1  0.978  0.243  0.502  1.0
  Na  Na1  1  0.022  0.757  0.498  1.0
  Na  Na2  1  0.739  0.264  0.249  1.0
  Na  Na3  1  0.761  0.264  0.749  1.0
  Na  Na4  1  0.522  0.243  0.002  1.0
  Na  Na5  1  0.478  0.757  0.998  1.0
  Na  Na6  1  0.239  0.736  0.251  1.0
  Na  Na7  1  0.261  0.736  0.751  1.0
  Li  Li8  1  0.910  0.690  0.789  1.0
  Li  Li9  1  0.863  0.761  0.993  1.0
  Li  Li10  1  0.637  0.761  0.493  1.0
  Li  Li11  1  0.590  0.690  0.289  1.0
  Li  Li12  1  0.410  0.310  0.711  1.0
  Li  Li13  1  0.363  0.239  0.507  1.0
  Li  Li14  1  0.137  0.239  0.007  1.0
  Li  Li15  1  0.090  0.310  0.211  1.0
  Co  Co16  1  0.873  0.794  0.223  1.0
  Co  Co17  1  0.627  0.794  0.723  1.0
  Co  Co18  1  0.373  0.206  0.277  1.0
  Co  Co19  1  0.127  0.206  0.777  1.0
  O  O20  1  0.971  0.558  0.210  1.0
  O  O21  1  0.006  0.026  0.206  1.0
  O  O22  1  0.784  0.600  0.430  1.0
  O  O23  1  0.782  0.923  0.566  1.0
  O  O24  1  0.718  0.923  0.066  1.0
  O  O25  1  0.716  0.600  0.930  1.0
  O  O26  1  0.494  0.026  0.706  1.0
  O  O27  1  0.529  0.558  0.710  1.0
  O  O28  1  0.471  0.442  0.290  1.0
  O  O29  1  0.506  0.974  0.294  1.0
  O  O30  1  0.284  0.400  0.070  1.0
  O  O31  1  0.282  0.077  0.934  1.0
  O  O32  1  0.218  0.077  0.434  1.0
  O  O33  1  0.216  0.400  0.570  1.0
  O  O34  1  0.994  0.974  0.794  1.0
  O  O35  1  0.029  0.442  0.790  1.0
[/CIF]
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The material described by Na2Li2CoO4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted NaO6 octahedra that share corners with two equivalent Co(1)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, edges with two equivalent Na(1)O6 octahedra,  an edgeedge with one Li(2)O4 tetrahedra, and edges with two equivalent Co(1)O4 tetrahedra. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), one O(3), and one O(4) atom. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form distorted LiO4 tetrahedra that share corners with four equivalent Na(1)O6 octahedra, corners with two equivalent Co(1)O4 tetrahedra,  an edgeedge with one Na(1)O6 octahedra, and  an edgeedge with one Co(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 27-38°. Co(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form CoO4 tetrahedra that share corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Li(2)O4 tetrahedra, edges with two equivalent Na(1)O6 octahedra, and  an edgeedge with one Li(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 40-55°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Na(1), two equivalent Na(2), one Li(1), one Li(2), and one Co(1) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(1), two equivalent Na(2), one Li(1), one Li(2), and one Co(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Na(2), two equivalent Na(1), one Li(1), one Li(2), and one Co(1) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Na(2), two equivalent Na(1), one Li(1), one Li(2), and one Co(1) atom. is represented by the CIF card [CIF]
data_Na2Li2CoO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.392
_cell_length_b   6.497
_cell_length_c   10.261
_cell_angle_alpha   51.149
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   435.692
_cell_formula_units_Z   4
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
  Na  Na0  1  0.978  0.243  0.502  1.0
  Na  Na1  1  0.022  0.757  0.498  1.0
  Na  Na2  1  0.739  0.264  0.249  1.0
  Na  Na3  1  0.761  0.264  0.749  1.0
  Na  Na4  1  0.522  0.243  0.002  1.0
  Na  Na5  1  0.478  0.757  0.998  1.0
  Na  Na6  1  0.239  0.736  0.251  1.0
  Na  Na7  1  0.261  0.736  0.751  1.0
  Li  Li8  1  0.910  0.690  0.789  1.0
  Li  Li9  1  0.863  0.761  0.993  1.0
  Li  Li10  1  0.637  0.761  0.493  1.0
  Li  Li11  1  0.590  0.690  0.289  1.0
  Li  Li12  1  0.410  0.310  0.711  1.0
  Li  Li13  1  0.363  0.239  0.507  1.0
  Li  Li14  1  0.137  0.239  0.007  1.0
  Li  Li15  1  0.090  0.310  0.211  1.0
  Co  Co16  1  0.873  0.794  0.223  1.0
  Co  Co17  1  0.627  0.794  0.723  1.0
  Co  Co18  1  0.373  0.206  0.277  1.0
  Co  Co19  1  0.127  0.206  0.777  1.0
  O  O20  1  0.971  0.558  0.210  1.0
  O  O21  1  0.006  0.026  0.206  1.0
  O  O22  1  0.784  0.600  0.430  1.0
  O  O23  1  0.782  0.923  0.566  1.0
  O  O24  1  0.718  0.923  0.066  1.0
  O  O25  1  0.716  0.600  0.930  1.0
  O  O26  1  0.494  0.026  0.706  1.0
  O  O27  1  0.529  0.558  0.710  1.0
  O  O28  1  0.471  0.442  0.290  1.0
  O  O29  1  0.506  0.974  0.294  1.0
  O  O30  1  0.284  0.400  0.070  1.0
  O  O31  1  0.282  0.077  0.934  1.0
  O  O32  1  0.218  0.077  0.434  1.0
  O  O33  1  0.216  0.400  0.570  1.0
  O  O34  1  0.994  0.974  0.794  1.0
  O  O35  1  0.029  0.442  0.790  1.0
[/CIF]
.