The structure described by Na3(CoO2)2 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to six equivalent O(1) atoms. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to four equivalent O(1) atoms. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a square co-planar geometry to four equivalent O(1) atoms. In the second Co site, Co(2) is bonded in a distorted square co-planar geometry to four equivalent O(1) atoms. O(1) is bonded to one Na(2), three equivalent Na(1), one Co(1), and one Co(2) atom to form a mixture of distorted edge, corner, and face-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 0-75°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na3(CoO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.966
_cell_length_b   4.966
_cell_length_c   10.534
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   109.329
_symmetry_Int_Tables_number   1
_cell_volume   245.184
_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
  Na  Na0  1  0.646  0.354  0.062  1.0
  Na  Na1  1  0.646  0.354  0.438  1.0
  Na  Na2  1  0.354  0.646  0.562  1.0
  Na  Na3  1  0.316  0.684  0.250  1.0
  Na  Na4  1  0.684  0.316  0.750  1.0
  Na  Na5  1  0.354  0.646  0.938  1.0
  Co  Co6  1  0.000  0.000  0.000  1.0
  Co  Co7  1  0.932  0.068  0.250  1.0
  Co  Co8  1  0.000  0.000  0.500  1.0
  Co  Co9  1  0.068  0.932  0.750  1.0
  O  O10  1  0.140  0.303  0.114  1.0
  O  O11  1  0.140  0.303  0.386  1.0
  O  O12  1  0.303  0.140  0.886  1.0
  O  O13  1  0.303  0.140  0.614  1.0
  O  O14  1  0.697  0.860  0.386  1.0
  O  O15  1  0.697  0.860  0.114  1.0
  O  O16  1  0.860  0.697  0.614  1.0
  O  O17  1  0.860  0.697  0.886  1.0
[/CIF]
.
The structure described by Na3(CoO2)2 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to six equivalent O(1) atoms. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to four equivalent O(1) atoms. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a square co-planar geometry to four equivalent O(1) atoms. In the second Co site, Co(2) is bonded in a distorted square co-planar geometry to four equivalent O(1) atoms. O(1) is bonded to one Na(2), three equivalent Na(1), one Co(1), and one Co(2) atom to form a mixture of distorted edge, corner, and face-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 0-75°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na3(CoO2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.966
_cell_length_b   4.966
_cell_length_c   10.534
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   109.329
_symmetry_Int_Tables_number   1
_cell_volume   245.184
_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
  Na  Na0  1  0.646  0.354  0.062  1.0
  Na  Na1  1  0.646  0.354  0.438  1.0
  Na  Na2  1  0.354  0.646  0.562  1.0
  Na  Na3  1  0.316  0.684  0.250  1.0
  Na  Na4  1  0.684  0.316  0.750  1.0
  Na  Na5  1  0.354  0.646  0.938  1.0
  Co  Co6  1  0.000  0.000  0.000  1.0
  Co  Co7  1  0.932  0.068  0.250  1.0
  Co  Co8  1  0.000  0.000  0.500  1.0
  Co  Co9  1  0.068  0.932  0.750  1.0
  O  O10  1  0.140  0.303  0.114  1.0
  O  O11  1  0.140  0.303  0.386  1.0
  O  O12  1  0.303  0.140  0.886  1.0
  O  O13  1  0.303  0.140  0.614  1.0
  O  O14  1  0.697  0.860  0.386  1.0
  O  O15  1  0.697  0.860  0.114  1.0
  O  O16  1  0.860  0.697  0.614  1.0
  O  O17  1  0.860  0.697  0.886  1.0
[/CIF]
.