The material described by Na2Fe2O5 crystallizes in the orthorhombic Ima2 space group. Na(1) is bonded in a 8-coordinate geometry to one O(2), three equivalent O(3), and four equivalent O(1) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form FeO6 octahedra that share corners with four equivalent Fe(1)O6 octahedra and corners with two equivalent Fe(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 8°. In the second Fe site, Fe(2) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form FeO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with two equivalent Fe(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 33°. There are three inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Na(1) and two equivalent Fe(1) atoms to form distorted ONa4Fe2 octahedra that share corners with two equivalent O(1)Na4Fe2 octahedra, corners with four equivalent O(2)Na2Fe2 tetrahedra, edges with two equivalent O(1)Na4Fe2 octahedra, and faces with four equivalent O(1)Na4Fe2 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded to two equivalent Na(1) and two equivalent Fe(2) atoms to form distorted ONa2Fe2 tetrahedra that share corners with eight equivalent O(1)Na4Fe2 octahedra and corners with two equivalent O(2)Na2Fe2 tetrahedra. The corner-sharing octahedral tilt angles range from 20-82°. In the third O site, O(3) is bonded in a 5-coordinate geometry to three equivalent Na(1), one Fe(1), and one Fe(2) atom. is represented by the CIF file [CIF]
data_Na2Fe2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.299
_cell_length_b   8.299
_cell_length_c   8.299
_cell_angle_alpha   141.635
_cell_angle_beta   141.016
_cell_angle_gamma   55.847
_symmetry_Int_Tables_number   1
_cell_volume   221.460
_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  0.871  0.392  0.476  1.0
  Na  Na1  1  0.585  0.105  0.476  1.0
  Na  Na2  1  0.129  0.605  0.520  1.0
  Na  Na3  1  0.415  0.892  0.520  1.0
  Fe  Fe4  1  0.000  0.991  0.991  1.0
  Fe  Fe5  1  0.820  0.789  0.109  1.0
  Fe  Fe6  1  0.500  0.491  0.991  1.0
  Fe  Fe7  1  0.180  0.289  0.969  1.0
  O  O8  1  0.761  0.250  0.992  1.0
  O  O9  1  0.758  0.750  0.489  1.0
  O  O10  1  0.881  0.126  0.507  1.0
  O  O11  1  0.810  0.837  0.925  1.0
  O  O12  1  0.589  0.615  0.925  1.0
  O  O13  1  0.190  0.115  0.027  1.0
  O  O14  1  0.411  0.337  0.027  1.0
  O  O15  1  0.119  0.626  0.245  1.0
  O  O16  1  0.242  0.731  0.992  1.0
  O  O17  1  0.239  0.231  0.489  1.0
[/CIF]
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The material described by Na2Fe2O5 crystallizes in the orthorhombic Ima2 space group. Na(1) is bonded in a 8-coordinate geometry to one O(2), three equivalent O(3), and four equivalent O(1) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form FeO6 octahedra that share corners with four equivalent Fe(1)O6 octahedra and corners with two equivalent Fe(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 8°. In the second Fe site, Fe(2) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form FeO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with two equivalent Fe(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 33°. There are three inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Na(1) and two equivalent Fe(1) atoms to form distorted ONa4Fe2 octahedra that share corners with two equivalent O(1)Na4Fe2 octahedra, corners with four equivalent O(2)Na2Fe2 tetrahedra, edges with two equivalent O(1)Na4Fe2 octahedra, and faces with four equivalent O(1)Na4Fe2 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded to two equivalent Na(1) and two equivalent Fe(2) atoms to form distorted ONa2Fe2 tetrahedra that share corners with eight equivalent O(1)Na4Fe2 octahedra and corners with two equivalent O(2)Na2Fe2 tetrahedra. The corner-sharing octahedral tilt angles range from 20-82°. In the third O site, O(3) is bonded in a 5-coordinate geometry to three equivalent Na(1), one Fe(1), and one Fe(2) atom. is represented by the CIF file [CIF]
data_Na2Fe2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.299
_cell_length_b   8.299
_cell_length_c   8.299
_cell_angle_alpha   141.635
_cell_angle_beta   141.016
_cell_angle_gamma   55.847
_symmetry_Int_Tables_number   1
_cell_volume   221.460
_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  0.871  0.392  0.476  1.0
  Na  Na1  1  0.585  0.105  0.476  1.0
  Na  Na2  1  0.129  0.605  0.520  1.0
  Na  Na3  1  0.415  0.892  0.520  1.0
  Fe  Fe4  1  0.000  0.991  0.991  1.0
  Fe  Fe5  1  0.820  0.789  0.109  1.0
  Fe  Fe6  1  0.500  0.491  0.991  1.0
  Fe  Fe7  1  0.180  0.289  0.969  1.0
  O  O8  1  0.761  0.250  0.992  1.0
  O  O9  1  0.758  0.750  0.489  1.0
  O  O10  1  0.881  0.126  0.507  1.0
  O  O11  1  0.810  0.837  0.925  1.0
  O  O12  1  0.589  0.615  0.925  1.0
  O  O13  1  0.190  0.115  0.027  1.0
  O  O14  1  0.411  0.337  0.027  1.0
  O  O15  1  0.119  0.626  0.245  1.0
  O  O16  1  0.242  0.731  0.992  1.0
  O  O17  1  0.239  0.231  0.489  1.0
[/CIF]
.