The material structure described by Na2IrO3 is Caswellsilverite-like structured and crystallizes in the monoclinic C2/m space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form NaO6 octahedra that share corners with two equivalent Na(2)O6 octahedra, corners with four equivalent Na(3)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with four equivalent Na(3)O6 octahedra, and edges with six equivalent Ir(1)O6 octahedra. The corner-sharing octahedral tilt angles are 14°. In the second Na site, Na(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form NaO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with four equivalent Ir(1)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with four equivalent Ir(1)O6 octahedra, and edges with six equivalent Na(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-14°. In the third Na site, Na(3) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form NaO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with four equivalent Ir(1)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with three equivalent Na(2)O6 octahedra, edges with three equivalent Na(3)O6 octahedra, and edges with four equivalent Ir(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-14°. Ir(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form IrO6 octahedra that share corners with two equivalent Na(2)O6 octahedra, corners with four equivalent Na(3)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with three equivalent Na(1)O6 octahedra, edges with three equivalent Ir(1)O6 octahedra, and edges with four equivalent Na(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-12°. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(2), two equivalent Na(3), and two equivalent Ir(1) atoms to form a mixture of edge and corner-sharing ONa4Ir2 octahedra. The corner-sharing octahedral tilt angles range from 0-11°. In the second O site, O(2) is bonded to one Na(1), one Na(2), two equivalent Na(3), and two equivalent Ir(1) atoms to form a mixture of edge and corner-sharing ONa4Ir2 octahedra. The corner-sharing octahedral tilt angles range from 0-9°. is represented by the CIF file [CIF]
data_Na2IrO3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.470
_cell_length_b   5.470
_cell_length_c   5.533
_cell_angle_alpha   99.699
_cell_angle_beta   99.699
_cell_angle_gamma   119.915
_symmetry_Int_Tables_number   1
_cell_volume   135.108
_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  0.000  0.000  0.000  1.0
  Na  Na1  1  0.500  0.500  0.500  1.0
  Na  Na2  1  0.160  0.840  0.500  1.0
  Na  Na3  1  0.840  0.160  0.500  1.0
  Ir  Ir4  1  0.333  0.667  0.000  1.0
  Ir  Ir5  1  0.667  0.333  0.000  1.0
  O  O6  1  0.561  0.930  0.793  1.0
  O  O7  1  0.930  0.561  0.793  1.0
  O  O8  1  0.439  0.070  0.207  1.0
  O  O9  1  0.070  0.439  0.207  1.0
  O  O10  1  0.704  0.704  0.209  1.0
  O  O11  1  0.296  0.296  0.791  1.0
[/CIF]
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The material structure described by Na2IrO3 is Caswellsilverite-like structured and crystallizes in the monoclinic C2/m space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form NaO6 octahedra that share corners with two equivalent Na(2)O6 octahedra, corners with four equivalent Na(3)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with four equivalent Na(3)O6 octahedra, and edges with six equivalent Ir(1)O6 octahedra. The corner-sharing octahedral tilt angles are 14°. In the second Na site, Na(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form NaO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with four equivalent Ir(1)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with four equivalent Ir(1)O6 octahedra, and edges with six equivalent Na(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-14°. In the third Na site, Na(3) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form NaO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with four equivalent Ir(1)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with three equivalent Na(2)O6 octahedra, edges with three equivalent Na(3)O6 octahedra, and edges with four equivalent Ir(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-14°. Ir(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form IrO6 octahedra that share corners with two equivalent Na(2)O6 octahedra, corners with four equivalent Na(3)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with three equivalent Na(1)O6 octahedra, edges with three equivalent Ir(1)O6 octahedra, and edges with four equivalent Na(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-12°. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(2), two equivalent Na(3), and two equivalent Ir(1) atoms to form a mixture of edge and corner-sharing ONa4Ir2 octahedra. The corner-sharing octahedral tilt angles range from 0-11°. In the second O site, O(2) is bonded to one Na(1), one Na(2), two equivalent Na(3), and two equivalent Ir(1) atoms to form a mixture of edge and corner-sharing ONa4Ir2 octahedra. The corner-sharing octahedral tilt angles range from 0-9°. is represented by the CIF file [CIF]
data_Na2IrO3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.470
_cell_length_b   5.470
_cell_length_c   5.533
_cell_angle_alpha   99.699
_cell_angle_beta   99.699
_cell_angle_gamma   119.915
_symmetry_Int_Tables_number   1
_cell_volume   135.108
_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  0.000  0.000  0.000  1.0
  Na  Na1  1  0.500  0.500  0.500  1.0
  Na  Na2  1  0.160  0.840  0.500  1.0
  Na  Na3  1  0.840  0.160  0.500  1.0
  Ir  Ir4  1  0.333  0.667  0.000  1.0
  Ir  Ir5  1  0.667  0.333  0.000  1.0
  O  O6  1  0.561  0.930  0.793  1.0
  O  O7  1  0.930  0.561  0.793  1.0
  O  O8  1  0.439  0.070  0.207  1.0
  O  O9  1  0.070  0.439  0.207  1.0
  O  O10  1  0.704  0.704  0.209  1.0
  O  O11  1  0.296  0.296  0.791  1.0
[/CIF]
.