The crystal structure described by Na2NiO2 crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(2) atoms. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to two equivalent O(2) and three equivalent O(1) atoms. Ni(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 7-coordinate geometry to two equivalent Na(1), three equivalent Na(2), and two equivalent Ni(1) atoms. In the second O site, O(2) is bonded to two equivalent Na(1), two equivalent Na(2), and two equivalent Ni(1) atoms to form a mixture of corner and edge-sharing ONa4Ni2 octahedra. The corner-sharing octahedral tilt angles are 54°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na2NiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.865
_cell_length_b   5.305
_cell_length_c   8.301
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   105.667
_symmetry_Int_Tables_number   1
_cell_volume   121.506
_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  0.395  0.791  0.152  1.0
  Na  Na1  1  0.851  0.703  0.831  1.0
  Na  Na2  1  0.605  0.209  0.652  1.0
  Na  Na3  1  0.149  0.297  0.331  1.0
  Ni  Ni4  1  0.122  0.244  0.998  1.0
  Ni  Ni5  1  0.878  0.756  0.498  1.0
  O  O6  1  0.722  0.445  0.094  1.0
  O  O7  1  0.520  0.040  0.910  1.0
  O  O8  1  0.278  0.555  0.594  1.0
  O  O9  1  0.480  0.960  0.410  1.0
[/CIF]
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The crystal structure described by Na2NiO2 crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(2) atoms. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to two equivalent O(2) and three equivalent O(1) atoms. Ni(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 7-coordinate geometry to two equivalent Na(1), three equivalent Na(2), and two equivalent Ni(1) atoms. In the second O site, O(2) is bonded to two equivalent Na(1), two equivalent Na(2), and two equivalent Ni(1) atoms to form a mixture of corner and edge-sharing ONa4Ni2 octahedra. The corner-sharing octahedral tilt angles are 54°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na2NiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.865
_cell_length_b   5.305
_cell_length_c   8.301
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   105.667
_symmetry_Int_Tables_number   1
_cell_volume   121.506
_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  0.395  0.791  0.152  1.0
  Na  Na1  1  0.851  0.703  0.831  1.0
  Na  Na2  1  0.605  0.209  0.652  1.0
  Na  Na3  1  0.149  0.297  0.331  1.0
  Ni  Ni4  1  0.122  0.244  0.998  1.0
  Ni  Ni5  1  0.878  0.756  0.498  1.0
  O  O6  1  0.722  0.445  0.094  1.0
  O  O7  1  0.520  0.040  0.910  1.0
  O  O8  1  0.278  0.555  0.594  1.0
  O  O9  1  0.480  0.960  0.410  1.0
[/CIF]
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