The compound described by Na3CuO2 crystallizes in the tetragonal P4_12_12 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted tetrahedral geometry to two equivalent O(1) and two equivalent O(2) atoms. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(2) atoms. In the third Na site, Na(3) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(2) atoms. In the fourth Na site, Na(4) is bonded in a 3-coordinate geometry to two equivalent O(1) and two equivalent O(2) atoms. Cu(1) is bonded in a linear geometry to one O(1) and one O(2) atom. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 7-coordinate geometry to one Na(1), one Na(3), two equivalent Na(2), two equivalent Na(4), and one Cu(1) atom. In the second O site, O(2) is bonded in a 7-coordinate geometry to one Na(1), one Na(3), two equivalent Na(2), two equivalent Na(4), and one Cu(1) atom. is represented by the CIF file [CIF]
data_Na3CuO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.868
_cell_length_b   7.868
_cell_length_c   11.582
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   716.920
_cell_formula_units_Z   8
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  0.015  0.985  0.750  1.0
  Na  Na1  1  0.026  0.555  0.748  1.0
  Na  Na2  1  0.048  0.048  0.500  1.0
  Na  Na3  1  0.055  0.474  0.498  1.0
  Na  Na4  1  0.151  0.265  0.895  1.0
  Na  Na5  1  0.235  0.651  0.145  1.0
  Na  Na6  1  0.265  0.151  0.105  1.0
  Na  Na7  1  0.349  0.765  0.355  1.0
  Na  Na8  1  0.445  0.974  0.752  1.0
  Na  Na9  1  0.452  0.548  0.750  1.0
  Na  Na10  1  0.474  0.055  0.502  1.0
  Na  Na11  1  0.485  0.485  0.500  1.0
  Na  Na12  1  0.515  0.515  0.000  1.0
  Na  Na13  1  0.526  0.945  0.002  1.0
  Na  Na14  1  0.548  0.452  0.250  1.0
  Na  Na15  1  0.555  0.026  0.252  1.0
  Na  Na16  1  0.651  0.235  0.855  1.0
  Na  Na17  1  0.735  0.849  0.605  1.0
  Na  Na18  1  0.765  0.349  0.645  1.0
  Na  Na19  1  0.849  0.735  0.395  1.0
  Na  Na20  1  0.945  0.526  0.998  1.0
  Na  Na21  1  0.952  0.952  0.000  1.0
  Na  Na22  1  0.974  0.445  0.248  1.0
  Na  Na23  1  0.985  0.015  0.250  1.0
  Cu  Cu24  1  0.236  0.764  0.591  1.0
  Cu  Cu25  1  0.236  0.764  0.909  1.0
  Cu  Cu26  1  0.264  0.264  0.341  1.0
  Cu  Cu27  1  0.264  0.264  0.659  1.0
  Cu  Cu28  1  0.736  0.736  0.159  1.0
  Cu  Cu29  1  0.736  0.736  0.841  1.0
  Cu  Cu30  1  0.764  0.236  0.409  1.0
  Cu  Cu31  1  0.764  0.236  0.091  1.0
  O  O32  1  0.006  0.761  0.588  1.0
  O  O33  1  0.035  0.266  0.666  1.0
  O  O34  1  0.234  0.535  0.916  1.0
  O  O35  1  0.239  0.994  0.912  1.0
  O  O36  1  0.261  0.494  0.338  1.0
  O  O37  1  0.266  0.035  0.334  1.0
  O  O38  1  0.465  0.766  0.584  1.0
  O  O39  1  0.494  0.261  0.662  1.0
  O  O40  1  0.506  0.739  0.162  1.0
  O  O41  1  0.535  0.234  0.084  1.0
  O  O42  1  0.734  0.965  0.834  1.0
  O  O43  1  0.739  0.506  0.838  1.0
  O  O44  1  0.761  0.006  0.412  1.0
  O  O45  1  0.766  0.465  0.416  1.0
  O  O46  1  0.965  0.734  0.166  1.0
  O  O47  1  0.994  0.239  0.088  1.0
[/CIF]
.
The compound described by Na3CuO2 crystallizes in the tetragonal P4_12_12 space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted tetrahedral geometry to two equivalent O(1) and two equivalent O(2) atoms. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(2) atoms. In the third Na site, Na(3) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(2) atoms. In the fourth Na site, Na(4) is bonded in a 3-coordinate geometry to two equivalent O(1) and two equivalent O(2) atoms. Cu(1) is bonded in a linear geometry to one O(1) and one O(2) atom. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 7-coordinate geometry to one Na(1), one Na(3), two equivalent Na(2), two equivalent Na(4), and one Cu(1) atom. In the second O site, O(2) is bonded in a 7-coordinate geometry to one Na(1), one Na(3), two equivalent Na(2), two equivalent Na(4), and one Cu(1) atom. is represented by the CIF file [CIF]
data_Na3CuO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.868
_cell_length_b   7.868
_cell_length_c   11.582
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   716.920
_cell_formula_units_Z   8
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  0.015  0.985  0.750  1.0
  Na  Na1  1  0.026  0.555  0.748  1.0
  Na  Na2  1  0.048  0.048  0.500  1.0
  Na  Na3  1  0.055  0.474  0.498  1.0
  Na  Na4  1  0.151  0.265  0.895  1.0
  Na  Na5  1  0.235  0.651  0.145  1.0
  Na  Na6  1  0.265  0.151  0.105  1.0
  Na  Na7  1  0.349  0.765  0.355  1.0
  Na  Na8  1  0.445  0.974  0.752  1.0
  Na  Na9  1  0.452  0.548  0.750  1.0
  Na  Na10  1  0.474  0.055  0.502  1.0
  Na  Na11  1  0.485  0.485  0.500  1.0
  Na  Na12  1  0.515  0.515  0.000  1.0
  Na  Na13  1  0.526  0.945  0.002  1.0
  Na  Na14  1  0.548  0.452  0.250  1.0
  Na  Na15  1  0.555  0.026  0.252  1.0
  Na  Na16  1  0.651  0.235  0.855  1.0
  Na  Na17  1  0.735  0.849  0.605  1.0
  Na  Na18  1  0.765  0.349  0.645  1.0
  Na  Na19  1  0.849  0.735  0.395  1.0
  Na  Na20  1  0.945  0.526  0.998  1.0
  Na  Na21  1  0.952  0.952  0.000  1.0
  Na  Na22  1  0.974  0.445  0.248  1.0
  Na  Na23  1  0.985  0.015  0.250  1.0
  Cu  Cu24  1  0.236  0.764  0.591  1.0
  Cu  Cu25  1  0.236  0.764  0.909  1.0
  Cu  Cu26  1  0.264  0.264  0.341  1.0
  Cu  Cu27  1  0.264  0.264  0.659  1.0
  Cu  Cu28  1  0.736  0.736  0.159  1.0
  Cu  Cu29  1  0.736  0.736  0.841  1.0
  Cu  Cu30  1  0.764  0.236  0.409  1.0
  Cu  Cu31  1  0.764  0.236  0.091  1.0
  O  O32  1  0.006  0.761  0.588  1.0
  O  O33  1  0.035  0.266  0.666  1.0
  O  O34  1  0.234  0.535  0.916  1.0
  O  O35  1  0.239  0.994  0.912  1.0
  O  O36  1  0.261  0.494  0.338  1.0
  O  O37  1  0.266  0.035  0.334  1.0
  O  O38  1  0.465  0.766  0.584  1.0
  O  O39  1  0.494  0.261  0.662  1.0
  O  O40  1  0.506  0.739  0.162  1.0
  O  O41  1  0.535  0.234  0.084  1.0
  O  O42  1  0.734  0.965  0.834  1.0
  O  O43  1  0.739  0.506  0.838  1.0
  O  O44  1  0.761  0.006  0.412  1.0
  O  O45  1  0.766  0.465  0.416  1.0
  O  O46  1  0.965  0.734  0.166  1.0
  O  O47  1  0.994  0.239  0.088  1.0
[/CIF]
.