The structure described by Na2CoO3 crystallizes in the orthorhombic Cmc2_1 space group. Na(1) is bonded to one O(2) and four equivalent O(1) atoms to form distorted NaO5 trigonal bipyramids that share corners with four equivalent Co(1)O4 tetrahedra, corners with five equivalent Na(1)O5 trigonal bipyramids,  an edgeedge with one Co(1)O4 tetrahedra, and edges with four equivalent Na(1)O5 trigonal bipyramids. Co(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form CoO4 tetrahedra that share corners with two equivalent Co(1)O4 tetrahedra, corners with eight equivalent Na(1)O5 trigonal bipyramids, and edges with two equivalent Na(1)O5 trigonal bipyramids. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to four equivalent Na(1) and one Co(1) atom. In the second O site, O(2) is bonded to two equivalent Na(1) and two equivalent Co(1) atoms to form distorted corner-sharing ONa2Co2 tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na2CoO3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.314
_cell_length_b   6.251
_cell_length_c   5.188
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   59.667
_symmetry_Int_Tables_number   1
_cell_volume   176.740
_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  0.830  0.675  0.520  1.0
  Na  Na1  1  0.495  0.675  0.020  1.0
  Na  Na2  1  0.505  0.325  0.520  1.0
  Na  Na3  1  0.170  0.325  0.020  1.0
  Co  Co4  1  0.841  0.000  0.049  1.0
  Co  Co5  1  0.159  0.000  0.549  1.0
  O  O6  1  0.835  0.727  0.981  1.0
  O  O7  1  0.439  0.727  0.481  1.0
  O  O8  1  0.561  0.273  0.981  1.0
  O  O9  1  0.165  0.273  0.481  1.0
  O  O10  1  0.889  1.000  0.406  1.0
  O  O11  1  0.111  0.000  0.906  1.0
[/CIF]
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The structure described by Na2CoO3 crystallizes in the orthorhombic Cmc2_1 space group. Na(1) is bonded to one O(2) and four equivalent O(1) atoms to form distorted NaO5 trigonal bipyramids that share corners with four equivalent Co(1)O4 tetrahedra, corners with five equivalent Na(1)O5 trigonal bipyramids,  an edgeedge with one Co(1)O4 tetrahedra, and edges with four equivalent Na(1)O5 trigonal bipyramids. Co(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form CoO4 tetrahedra that share corners with two equivalent Co(1)O4 tetrahedra, corners with eight equivalent Na(1)O5 trigonal bipyramids, and edges with two equivalent Na(1)O5 trigonal bipyramids. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to four equivalent Na(1) and one Co(1) atom. In the second O site, O(2) is bonded to two equivalent Na(1) and two equivalent Co(1) atoms to form distorted corner-sharing ONa2Co2 tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na2CoO3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.314
_cell_length_b   6.251
_cell_length_c   5.188
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   59.667
_symmetry_Int_Tables_number   1
_cell_volume   176.740
_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  0.830  0.675  0.520  1.0
  Na  Na1  1  0.495  0.675  0.020  1.0
  Na  Na2  1  0.505  0.325  0.520  1.0
  Na  Na3  1  0.170  0.325  0.020  1.0
  Co  Co4  1  0.841  0.000  0.049  1.0
  Co  Co5  1  0.159  0.000  0.549  1.0
  O  O6  1  0.835  0.727  0.981  1.0
  O  O7  1  0.439  0.727  0.481  1.0
  O  O8  1  0.561  0.273  0.981  1.0
  O  O9  1  0.165  0.273  0.481  1.0
  O  O10  1  0.889  1.000  0.406  1.0
  O  O11  1  0.111  0.000  0.906  1.0
[/CIF]
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