The structure described by Na2CoO3 is Caswellsilverite-like structured and crystallizes in the triclinic P1 space group. There are eight inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(11), one O(3), one O(5), one O(7), and one O(9) atom to form distorted NaO6 octahedra that share corners with two equivalent Na(4)O6 octahedra, corners with two equivalent Co(1)O6 octahedra, corners with two equivalent Co(4)O6 octahedra, edges with two equivalent Na(4)O6 octahedra, edges with two equivalent Na(6)O6 octahedra, edges with two equivalent Co(2)O6 octahedra, and edges with two equivalent Co(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-20°. In the second Na site, Na(2) is bonded to one O(10), one O(12), one O(2), one O(4), one O(6), and one O(8) atom to form distorted NaO6 octahedra that share corners with two equivalent Na(3)O6 octahedra, corners with two equivalent Co(2)O6 octahedra, corners with two equivalent Co(3)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra, edges with two equivalent Na(3)O6 octahedra, edges with two equivalent Co(1)O6 octahedra, and edges with two equivalent Co(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 13-19°. In the third Na site, Na(3) is bonded to one O(10), one O(12), one O(2), one O(4), one O(6), and one O(8) atom to form NaO6 octahedra that share corners with two equivalent Na(2)O6 octahedra, corners with two equivalent Na(6)O6 octahedra,  an edgeedge with one Co(2)O6 octahedra,  an edgeedge with one Co(3)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Co(1)O6 octahedra, and edges with two equivalent Co(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 18-20°. In the fourth Na site, Na(4) is bonded to one O(1), one O(11), one O(3), one O(5), one O(7), and one O(9) atom to form NaO6 octahedra that share corners with two equivalent Na(1)O6 octahedra,  an edgeedge with one Co(1)O6 octahedra,  an edgeedge with one Co(4)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Na(6)O6 octahedra, edges with two equivalent Co(2)O6 octahedra, and edges with two equivalent Co(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 18-20°. In the fifth Na site, Na(5) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(2), one O(4), one O(5), and one O(8) atom. In the sixth Na site, Na(6) is bonded to one O(1), one O(12), one O(3), one O(6), one O(7), and one O(9) atom to form distorted NaO6 octahedra that share corners with two equivalent Na(3)O6 octahedra, corners with two equivalent Co(2)O6 octahedra, corners with two equivalent Co(3)O6 octahedra,  an edgeedge with one Na(2)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Na(4)O6 octahedra, edges with two equivalent Co(3)O6 octahedra, and edges with two equivalent Co(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 14-20°. In the seventh Na site, Na(7) is bonded in a 6-coordinate geometry to one O(12), one O(2), one O(4), one O(6), one O(7), and one O(9) atom. In the eighth Na site, Na(8) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(11), one O(3), one O(5), and one O(8) atom. There are four inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(10), one O(11), one O(2), one O(4), one O(5), and one O(8) atom to form CoO6 octahedra that share corners with two equivalent Na(1)O6 octahedra,  an edgeedge with one Na(4)O6 octahedra,  an edgeedge with one Co(4)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Na(3)O6 octahedra, and edges with two equivalent Co(2)O6 octahedra. The corner-sharing octahedral tilt angles are 14°. In the second Co site, Co(2) is bonded to one O(1), one O(10), one O(11), one O(3), one O(5), and one O(8) atom to form CoO6 octahedra that share corners with two equivalent Na(2)O6 octahedra, corners with two equivalent Na(6)O6 octahedra,  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Co(3)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Na(4)O6 octahedra, and edges with two equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 14-16°. In the third Co site, Co(3) is bonded to one O(1), one O(12), one O(3), one O(6), one O(7), and one O(9) atom to form CoO6 octahedra that share corners with two equivalent Na(2)O6 octahedra, corners with two equivalent Na(6)O6 octahedra,  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Co(2)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Na(4)O6 octahedra, edges with two equivalent Na(6)O6 octahedra, and edges with two equivalent Co(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 13-18°. In the fourth Co site, Co(4) is bonded to one O(12), one O(2), one O(4), one O(6), one O(7), and one O(9) atom to form CoO6 octahedra that share corners with two equivalent Na(1)O6 octahedra,  an edgeedge with one Na(4)O6 octahedra,  an edgeedge with one Co(1)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Na(3)O6 octahedra, edges with two equivalent Na(6)O6 octahedra, and edges with two equivalent Co(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-11°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(4), one Na(6), one Na(8), one Co(2), and one Co(3) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 2-15°. In the second O site, O(2) is bonded to one Na(2), one Na(3), one Na(5), one Na(7), one Co(1), and one Co(4) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 2-14°. In the third O site, O(3) is bonded to one Na(1), one Na(4), one Na(6), one Na(8), one Co(2), and one Co(3) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 2-14°. In the fourth O site, O(4) is bonded to one Na(2), one Na(3), one Na(5), one Na(7), one Co(1), and one Co(4) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 2-13°. In the fifth O site, O(5) is bonded to one Na(1), one Na(4), one Na(5), one Na(8), one Co(1), and one Co(2) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 2-14°. In the sixth O site, O(6) is bonded to one Na(2), one Na(3), one Na(6), one Na(7), one Co(3), and one Co(4) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 1-15°. In the seventh O site, O(7) is bonded to one Na(1), one Na(4), one Na(6), one Na(7), one Co(3), and one Co(4) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 1-16°. In the eighth O site, O(8) is bonded to one Na(2), one Na(3), one Na(5), one Na(8), one Co(1), and one Co(2) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 0-14°. In the ninth O site, O(9) is bonded to one Na(1), one Na(4), one Na(6), one Na(7), one Co(3), and one Co(4) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 2-16°. In the tenth O site, O(10) is bonded to one Na(2), one Na(3), one Na(5), one Na(8), one Co(1), and one Co(2) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 1-14°. In the eleventh O site, O(11) is bonded to one Na(1), one Na(4), one Na(5), one Na(8), one Co(1), and one Co(2) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 1-14°. In the twelfth O site, O(12) is bonded to one Na(2), one Na(3), one Na(6), one Na(7), one Co(3), and one Co(4) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 0-15°. is represented by the CIF card [CIF]
data_Na2CoO3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.229
_cell_length_b   5.243
_cell_length_c   5.688
_cell_angle_alpha   99.429
_cell_angle_beta   99.684
_cell_angle_gamma   119.586
_symmetry_Int_Tables_number   1
_cell_volume   128.008
_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  0.329  0.665  0.001  1.0
  Co  Co1  1  0.669  0.327  1.000  1.0
  Na  Na2  1  0.500  0.500  0.500  1.0
  Na  Na3  1  0.999  0.999  0.000  1.0
  Na  Na4  1  0.842  0.158  0.500  1.0
  Na  Na5  1  0.158  0.844  0.500  1.0
  O  O6  1  0.315  0.312  0.801  1.0
  O  O7  1  0.684  0.686  0.197  1.0
  O  O8  1  0.447  0.066  0.196  1.0
  O  O9  1  0.055  0.443  0.201  1.0
  O  O10  1  0.561  0.948  0.800  1.0
  O  O11  1  0.941  0.554  0.804  1.0
[/CIF]
.
The structure described by Na2CoO3 is Caswellsilverite-like structured and crystallizes in the triclinic P1 space group. There are eight inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(11), one O(3), one O(5), one O(7), and one O(9) atom to form distorted NaO6 octahedra that share corners with two equivalent Na(4)O6 octahedra, corners with two equivalent Co(1)O6 octahedra, corners with two equivalent Co(4)O6 octahedra, edges with two equivalent Na(4)O6 octahedra, edges with two equivalent Na(6)O6 octahedra, edges with two equivalent Co(2)O6 octahedra, and edges with two equivalent Co(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-20°. In the second Na site, Na(2) is bonded to one O(10), one O(12), one O(2), one O(4), one O(6), and one O(8) atom to form distorted NaO6 octahedra that share corners with two equivalent Na(3)O6 octahedra, corners with two equivalent Co(2)O6 octahedra, corners with two equivalent Co(3)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra, edges with two equivalent Na(3)O6 octahedra, edges with two equivalent Co(1)O6 octahedra, and edges with two equivalent Co(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 13-19°. In the third Na site, Na(3) is bonded to one O(10), one O(12), one O(2), one O(4), one O(6), and one O(8) atom to form NaO6 octahedra that share corners with two equivalent Na(2)O6 octahedra, corners with two equivalent Na(6)O6 octahedra,  an edgeedge with one Co(2)O6 octahedra,  an edgeedge with one Co(3)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Co(1)O6 octahedra, and edges with two equivalent Co(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 18-20°. In the fourth Na site, Na(4) is bonded to one O(1), one O(11), one O(3), one O(5), one O(7), and one O(9) atom to form NaO6 octahedra that share corners with two equivalent Na(1)O6 octahedra,  an edgeedge with one Co(1)O6 octahedra,  an edgeedge with one Co(4)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Na(6)O6 octahedra, edges with two equivalent Co(2)O6 octahedra, and edges with two equivalent Co(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 18-20°. In the fifth Na site, Na(5) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(2), one O(4), one O(5), and one O(8) atom. In the sixth Na site, Na(6) is bonded to one O(1), one O(12), one O(3), one O(6), one O(7), and one O(9) atom to form distorted NaO6 octahedra that share corners with two equivalent Na(3)O6 octahedra, corners with two equivalent Co(2)O6 octahedra, corners with two equivalent Co(3)O6 octahedra,  an edgeedge with one Na(2)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Na(4)O6 octahedra, edges with two equivalent Co(3)O6 octahedra, and edges with two equivalent Co(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 14-20°. In the seventh Na site, Na(7) is bonded in a 6-coordinate geometry to one O(12), one O(2), one O(4), one O(6), one O(7), and one O(9) atom. In the eighth Na site, Na(8) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(11), one O(3), one O(5), and one O(8) atom. There are four inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(10), one O(11), one O(2), one O(4), one O(5), and one O(8) atom to form CoO6 octahedra that share corners with two equivalent Na(1)O6 octahedra,  an edgeedge with one Na(4)O6 octahedra,  an edgeedge with one Co(4)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Na(3)O6 octahedra, and edges with two equivalent Co(2)O6 octahedra. The corner-sharing octahedral tilt angles are 14°. In the second Co site, Co(2) is bonded to one O(1), one O(10), one O(11), one O(3), one O(5), and one O(8) atom to form CoO6 octahedra that share corners with two equivalent Na(2)O6 octahedra, corners with two equivalent Na(6)O6 octahedra,  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Co(3)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Na(4)O6 octahedra, and edges with two equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 14-16°. In the third Co site, Co(3) is bonded to one O(1), one O(12), one O(3), one O(6), one O(7), and one O(9) atom to form CoO6 octahedra that share corners with two equivalent Na(2)O6 octahedra, corners with two equivalent Na(6)O6 octahedra,  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Co(2)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Na(4)O6 octahedra, edges with two equivalent Na(6)O6 octahedra, and edges with two equivalent Co(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 13-18°. In the fourth Co site, Co(4) is bonded to one O(12), one O(2), one O(4), one O(6), one O(7), and one O(9) atom to form CoO6 octahedra that share corners with two equivalent Na(1)O6 octahedra,  an edgeedge with one Na(4)O6 octahedra,  an edgeedge with one Co(1)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Na(3)O6 octahedra, edges with two equivalent Na(6)O6 octahedra, and edges with two equivalent Co(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-11°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(4), one Na(6), one Na(8), one Co(2), and one Co(3) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 2-15°. In the second O site, O(2) is bonded to one Na(2), one Na(3), one Na(5), one Na(7), one Co(1), and one Co(4) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 2-14°. In the third O site, O(3) is bonded to one Na(1), one Na(4), one Na(6), one Na(8), one Co(2), and one Co(3) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 2-14°. In the fourth O site, O(4) is bonded to one Na(2), one Na(3), one Na(5), one Na(7), one Co(1), and one Co(4) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 2-13°. In the fifth O site, O(5) is bonded to one Na(1), one Na(4), one Na(5), one Na(8), one Co(1), and one Co(2) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 2-14°. In the sixth O site, O(6) is bonded to one Na(2), one Na(3), one Na(6), one Na(7), one Co(3), and one Co(4) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 1-15°. In the seventh O site, O(7) is bonded to one Na(1), one Na(4), one Na(6), one Na(7), one Co(3), and one Co(4) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 1-16°. In the eighth O site, O(8) is bonded to one Na(2), one Na(3), one Na(5), one Na(8), one Co(1), and one Co(2) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 0-14°. In the ninth O site, O(9) is bonded to one Na(1), one Na(4), one Na(6), one Na(7), one Co(3), and one Co(4) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 2-16°. In the tenth O site, O(10) is bonded to one Na(2), one Na(3), one Na(5), one Na(8), one Co(1), and one Co(2) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 1-14°. In the eleventh O site, O(11) is bonded to one Na(1), one Na(4), one Na(5), one Na(8), one Co(1), and one Co(2) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 1-14°. In the twelfth O site, O(12) is bonded to one Na(2), one Na(3), one Na(6), one Na(7), one Co(3), and one Co(4) atom to form a mixture of distorted corner and edge-sharing ONa4Co2 octahedra. The corner-sharing octahedral tilt angles range from 0-15°. is represented by the CIF card [CIF]
data_Na2CoO3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.229
_cell_length_b   5.243
_cell_length_c   5.688
_cell_angle_alpha   99.429
_cell_angle_beta   99.684
_cell_angle_gamma   119.586
_symmetry_Int_Tables_number   1
_cell_volume   128.008
_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  0.329  0.665  0.001  1.0
  Co  Co1  1  0.669  0.327  1.000  1.0
  Na  Na2  1  0.500  0.500  0.500  1.0
  Na  Na3  1  0.999  0.999  0.000  1.0
  Na  Na4  1  0.842  0.158  0.500  1.0
  Na  Na5  1  0.158  0.844  0.500  1.0
  O  O6  1  0.315  0.312  0.801  1.0
  O  O7  1  0.684  0.686  0.197  1.0
  O  O8  1  0.447  0.066  0.196  1.0
  O  O9  1  0.055  0.443  0.201  1.0
  O  O10  1  0.561  0.948  0.800  1.0
  O  O11  1  0.941  0.554  0.804  1.0
[/CIF]
.