The structure described by Na6CoO4 crystallizes in the hexagonal P6_3mc space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1) and three equivalent O(2) atoms to form distorted NaO4 trigonal pyramids that share corners with two equivalent Co(1)O4 tetrahedra, corners with eight equivalent Na(1)O4 trigonal pyramids, and  an edgeedge with one Co(1)O4 tetrahedra. In the second Na site, Na(2) is bonded in a 3-coordinate geometry to one O(1) and four equivalent O(2) atoms. Co(1) is bonded to one O(1) and three equivalent O(2) atoms to form CoO4 tetrahedra that share corners with six equivalent Na(1)O4 trigonal pyramids and edges with three equivalent Na(1)O4 trigonal pyramids. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 7-coordinate geometry to three equivalent Na(1), three equivalent Na(2), and one Co(1) atom. In the second O site, O(2) is bonded in a 8-coordinate geometry to three equivalent Na(1), four equivalent Na(2), and one Co(1) atom. is represented by the CIF card [CIF]
data_Na6CoO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.895
_cell_length_b   7.657
_cell_length_c   7.657
_cell_angle_alpha   119.998
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   299.312
_cell_formula_units_Z   2
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
  Co  Co0  1  0.742  0.667  0.333  1.0
  Co  Co1  1  0.242  0.333  0.667  1.0
  Na  Na2  1  0.464  0.285  0.142  1.0
  Na  Na3  1  0.464  0.858  0.715  1.0
  Na  Na4  1  0.964  0.142  0.858  1.0
  Na  Na5  1  0.464  0.858  0.142  1.0
  Na  Na6  1  0.964  0.142  0.285  1.0
  Na  Na7  1  0.964  0.715  0.858  1.0
  Na  Na8  1  0.132  0.537  0.463  1.0
  Na  Na9  1  0.132  0.537  0.074  1.0
  Na  Na10  1  0.132  0.926  0.463  1.0
  Na  Na11  1  0.632  0.074  0.537  1.0
  Na  Na12  1  0.632  0.463  0.926  1.0
  Na  Na13  1  0.632  0.463  0.537  1.0
  O  O14  1  0.405  0.667  0.333  1.0
  O  O15  1  0.905  0.333  0.667  1.0
  O  O16  1  0.854  0.379  0.189  1.0
  O  O17  1  0.854  0.811  0.621  1.0
  O  O18  1  0.854  0.811  0.189  1.0
  O  O19  1  0.354  0.189  0.811  1.0
  O  O20  1  0.354  0.189  0.379  1.0
  O  O21  1  0.354  0.621  0.811  1.0
[/CIF]
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The structure described by Na6CoO4 crystallizes in the hexagonal P6_3mc space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1) and three equivalent O(2) atoms to form distorted NaO4 trigonal pyramids that share corners with two equivalent Co(1)O4 tetrahedra, corners with eight equivalent Na(1)O4 trigonal pyramids, and  an edgeedge with one Co(1)O4 tetrahedra. In the second Na site, Na(2) is bonded in a 3-coordinate geometry to one O(1) and four equivalent O(2) atoms. Co(1) is bonded to one O(1) and three equivalent O(2) atoms to form CoO4 tetrahedra that share corners with six equivalent Na(1)O4 trigonal pyramids and edges with three equivalent Na(1)O4 trigonal pyramids. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 7-coordinate geometry to three equivalent Na(1), three equivalent Na(2), and one Co(1) atom. In the second O site, O(2) is bonded in a 8-coordinate geometry to three equivalent Na(1), four equivalent Na(2), and one Co(1) atom. is represented by the CIF card [CIF]
data_Na6CoO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.895
_cell_length_b   7.657
_cell_length_c   7.657
_cell_angle_alpha   119.998
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   299.312
_cell_formula_units_Z   2
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
  Co  Co0  1  0.742  0.667  0.333  1.0
  Co  Co1  1  0.242  0.333  0.667  1.0
  Na  Na2  1  0.464  0.285  0.142  1.0
  Na  Na3  1  0.464  0.858  0.715  1.0
  Na  Na4  1  0.964  0.142  0.858  1.0
  Na  Na5  1  0.464  0.858  0.142  1.0
  Na  Na6  1  0.964  0.142  0.285  1.0
  Na  Na7  1  0.964  0.715  0.858  1.0
  Na  Na8  1  0.132  0.537  0.463  1.0
  Na  Na9  1  0.132  0.537  0.074  1.0
  Na  Na10  1  0.132  0.926  0.463  1.0
  Na  Na11  1  0.632  0.074  0.537  1.0
  Na  Na12  1  0.632  0.463  0.926  1.0
  Na  Na13  1  0.632  0.463  0.537  1.0
  O  O14  1  0.405  0.667  0.333  1.0
  O  O15  1  0.905  0.333  0.667  1.0
  O  O16  1  0.854  0.379  0.189  1.0
  O  O17  1  0.854  0.811  0.621  1.0
  O  O18  1  0.854  0.811  0.189  1.0
  O  O19  1  0.354  0.189  0.811  1.0
  O  O20  1  0.354  0.189  0.379  1.0
  O  O21  1  0.354  0.621  0.811  1.0
[/CIF]
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