The crystal structure described by Na5CoO4 crystallizes in the orthorhombic Pmn2_1 space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 5-coordinate geometry to one O(1), two equivalent O(2), and two equivalent O(3) atoms. In the second Na site, Na(2) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form distorted NaO4 tetrahedra that share corners with two equivalent Na(3)O4 tetrahedra, corners with two equivalent Co(1)O4 tetrahedra, corners with four equivalent Na(2)O4 tetrahedra,  an edgeedge with one Na(3)O4 tetrahedra, and  an edgeedge with one Co(1)O4 tetrahedra. In the third Na site, Na(3) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form distorted NaO4 tetrahedra that share corners with four equivalent Na(2)O4 tetrahedra, corners with four equivalent Co(1)O4 tetrahedra, and edges with two equivalent Na(2)O4 tetrahedra. Co(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form distorted CoO4 tetrahedra that share corners with four equivalent Na(2)O4 tetrahedra, corners with four equivalent Na(3)O4 tetrahedra, and edges with two equivalent Na(2)O4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Na(3), two equivalent Na(1), two equivalent Na(2), and one Co(1) atom to form a mixture of distorted edge and corner-sharing ONa5Co pentagonal pyramids. The corner-sharing octahedral tilt angles range from 69-71°. In the second O site, O(2) is bonded in a 8-coordinate geometry to one Na(3), two equivalent Na(2), four equivalent Na(1), and one Co(1) atom. In the third O site, O(3) is bonded to one Na(3), two equivalent Na(1), two equivalent Na(2), and one Co(1) atom to form a mixture of edge and corner-sharing ONa5Co octahedra. The corner-sharing octahedral tilt angles range from 40-53°. is represented by the CIF card [CIF]
data_Na5CoO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.921
_cell_length_b   6.073
_cell_length_c   7.671
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   275.844
_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  0.932  0.068  0.316  1.0
  Na  Na1  1  0.932  0.068  0.684  1.0
  Na  Na2  1  0.749  0.611  0.699  1.0
  Na  Na3  1  0.749  0.611  0.301  1.0
  Na  Na4  1  0.746  0.325  0.000  1.0
  Na  Na5  1  0.432  0.932  0.816  1.0
  Na  Na6  1  0.432  0.932  0.184  1.0
  Na  Na7  1  0.249  0.389  0.801  1.0
  Na  Na8  1  0.249  0.389  0.199  1.0
  Na  Na9  1  0.246  0.675  0.500  1.0
  Co  Co10  1  0.995  0.826  0.000  1.0
  Co  Co11  1  0.495  0.174  0.500  1.0
  O  O12  1  0.689  0.741  0.000  1.0
  O  O13  1  0.597  0.872  0.500  1.0
  O  O14  1  0.601  0.267  0.279  1.0
  O  O15  1  0.601  0.267  0.721  1.0
  O  O16  1  0.189  0.259  0.500  1.0
  O  O17  1  0.097  0.129  0.000  1.0
  O  O18  1  0.101  0.733  0.779  1.0
  O  O19  1  0.101  0.733  0.221  1.0
[/CIF]
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The crystal structure described by Na5CoO4 crystallizes in the orthorhombic Pmn2_1 space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 5-coordinate geometry to one O(1), two equivalent O(2), and two equivalent O(3) atoms. In the second Na site, Na(2) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form distorted NaO4 tetrahedra that share corners with two equivalent Na(3)O4 tetrahedra, corners with two equivalent Co(1)O4 tetrahedra, corners with four equivalent Na(2)O4 tetrahedra,  an edgeedge with one Na(3)O4 tetrahedra, and  an edgeedge with one Co(1)O4 tetrahedra. In the third Na site, Na(3) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form distorted NaO4 tetrahedra that share corners with four equivalent Na(2)O4 tetrahedra, corners with four equivalent Co(1)O4 tetrahedra, and edges with two equivalent Na(2)O4 tetrahedra. Co(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form distorted CoO4 tetrahedra that share corners with four equivalent Na(2)O4 tetrahedra, corners with four equivalent Na(3)O4 tetrahedra, and edges with two equivalent Na(2)O4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Na(3), two equivalent Na(1), two equivalent Na(2), and one Co(1) atom to form a mixture of distorted edge and corner-sharing ONa5Co pentagonal pyramids. The corner-sharing octahedral tilt angles range from 69-71°. In the second O site, O(2) is bonded in a 8-coordinate geometry to one Na(3), two equivalent Na(2), four equivalent Na(1), and one Co(1) atom. In the third O site, O(3) is bonded to one Na(3), two equivalent Na(1), two equivalent Na(2), and one Co(1) atom to form a mixture of edge and corner-sharing ONa5Co octahedra. The corner-sharing octahedral tilt angles range from 40-53°. is represented by the CIF card [CIF]
data_Na5CoO4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.921
_cell_length_b   6.073
_cell_length_c   7.671
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   275.844
_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  0.932  0.068  0.316  1.0
  Na  Na1  1  0.932  0.068  0.684  1.0
  Na  Na2  1  0.749  0.611  0.699  1.0
  Na  Na3  1  0.749  0.611  0.301  1.0
  Na  Na4  1  0.746  0.325  0.000  1.0
  Na  Na5  1  0.432  0.932  0.816  1.0
  Na  Na6  1  0.432  0.932  0.184  1.0
  Na  Na7  1  0.249  0.389  0.801  1.0
  Na  Na8  1  0.249  0.389  0.199  1.0
  Na  Na9  1  0.246  0.675  0.500  1.0
  Co  Co10  1  0.995  0.826  0.000  1.0
  Co  Co11  1  0.495  0.174  0.500  1.0
  O  O12  1  0.689  0.741  0.000  1.0
  O  O13  1  0.597  0.872  0.500  1.0
  O  O14  1  0.601  0.267  0.279  1.0
  O  O15  1  0.601  0.267  0.721  1.0
  O  O16  1  0.189  0.259  0.500  1.0
  O  O17  1  0.097  0.129  0.000  1.0
  O  O18  1  0.101  0.733  0.779  1.0
  O  O19  1  0.101  0.733  0.221  1.0
[/CIF]
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