The structure described by Na4Fe2O5 crystallizes in the monoclinic P2_1/c space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a 5-coordinate geometry to one O(1), one O(4), one O(5), and two equivalent O(3) atoms. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(5), and two equivalent O(4) atoms. In the third Na site, Na(3) is bonded to one O(2), one O(3), one O(5), and two equivalent O(4) atoms to form distorted NaO5 trigonal bipyramids that share  a cornercorner with one Fe(2)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Na(4)O5 trigonal bipyramids, edges with two equivalent Fe(2)O4 tetrahedra,  an edgeedge with one Na(3)O5 trigonal bipyramid, and  an edgeedge with one Na(4)O5 trigonal bipyramid. In the fourth Na site, Na(4) is bonded to one O(1), one O(2), one O(5), and two equivalent O(3) atoms to form distorted NaO5 trigonal bipyramids that share  a cornercorner with one Fe(2)O4 tetrahedra, corners with three equivalent Fe(1)O4 tetrahedra, corners with two equivalent Na(3)O5 trigonal bipyramids,  an edgeedge with one Fe(1)O4 tetrahedra,  an edgeedge with one Fe(2)O4 tetrahedra,  an edgeedge with one Na(3)O5 trigonal bipyramid, and  an edgeedge with one Na(4)O5 trigonal bipyramid. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), one O(5), and two equivalent O(1) atoms to form FeO4 tetrahedra that share  a cornercorner with one Fe(2)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Na(3)O5 trigonal bipyramids, corners with three equivalent Na(4)O5 trigonal bipyramids, and  an edgeedge with one Na(4)O5 trigonal bipyramid. In the second Fe site, Fe(2) is bonded to one O(4), one O(5), and two equivalent O(2) atoms to form FeO4 tetrahedra that share  a cornercorner with one Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra,  a cornercorner with one Na(3)O5 trigonal bipyramid,  a cornercorner with one Na(4)O5 trigonal bipyramid,  an edgeedge with one Na(4)O5 trigonal bipyramid, and edges with two equivalent Na(3)O5 trigonal bipyramids. There are five inequivalent O sites. In the first O site, O(4) is bonded to one Na(1), two equivalent Na(2), two equivalent Na(3), and one Fe(2) atom to form a mixture of distorted edge and corner-sharing ONa5Fe octahedra. The corner-sharing octahedral tilt angles range from 42-52°. In the second O site, O(5) is bonded in a 6-coordinate geometry to one Na(1), one Na(2), one Na(3), one Na(4), one Fe(1), and one Fe(2) atom. In the third O site, O(1) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(4), and two equivalent Fe(1) atoms. In the fourth O site, O(2) is bonded in a 5-coordinate geometry to one Na(2), one Na(3), one Na(4), and two equivalent Fe(2) atoms. In the fifth O site, O(3) is bonded to one Na(3), two equivalent Na(1), two equivalent Na(4), and one Fe(1) atom to form a mixture of edge and corner-sharing ONa5Fe octahedra. The corner-sharing octahedral tilt angles range from 42-52°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na4Fe2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.773
_cell_length_b   9.254
_cell_length_c   13.127
_cell_angle_alpha   62.066
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   619.549
_cell_formula_units_Z   4
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  0.927  0.194  0.967  1.0
  Na  Na1  1  0.427  0.806  0.533  1.0
  Na  Na2  1  0.114  0.606  0.878  1.0
  Na  Na3  1  0.573  0.194  0.467  1.0
  Na  Na4  1  0.411  0.298  0.038  1.0
  Na  Na5  1  0.911  0.702  0.462  1.0
  Na  Na6  1  0.589  0.702  0.962  1.0
  Na  Na7  1  0.089  0.298  0.538  1.0
  Na  Na8  1  0.619  0.870  0.133  1.0
  Na  Na9  1  0.119  0.130  0.367  1.0
  Na  Na10  1  0.381  0.130  0.867  1.0
  Na  Na11  1  0.881  0.870  0.633  1.0
  Na  Na12  1  0.386  0.606  0.378  1.0
  Na  Na13  1  0.886  0.394  0.122  1.0
  Na  Na14  1  0.614  0.394  0.622  1.0
  Na  Na15  1  0.073  0.806  0.033  1.0
  Fe  Fe16  1  0.658  0.044  0.297  1.0
  Fe  Fe17  1  0.342  0.956  0.703  1.0
  Fe  Fe18  1  0.842  0.044  0.797  1.0
  Fe  Fe19  1  0.615  0.543  0.801  1.0
  Fe  Fe20  1  0.115  0.457  0.699  1.0
  Fe  Fe21  1  0.385  0.457  0.199  1.0
  Fe  Fe22  1  0.885  0.543  0.301  1.0
  Fe  Fe23  1  0.158  0.956  0.203  1.0
  O  O24  1  0.933  0.112  0.200  1.0
  O  O25  1  0.329  0.419  0.823  1.0
  O  O26  1  0.171  0.419  0.323  1.0
  O  O27  1  0.671  0.581  0.177  1.0
  O  O28  1  0.260  0.031  0.053  1.0
  O  O29  1  0.760  0.969  0.447  1.0
  O  O30  1  0.740  0.969  0.947  1.0
  O  O31  1  0.240  0.031  0.553  1.0
  O  O32  1  0.761  0.447  0.943  1.0
  O  O33  1  0.261  0.553  0.557  1.0
  O  O34  1  0.239  0.553  0.057  1.0
  O  O35  1  0.739  0.447  0.443  1.0
  O  O36  1  0.981  0.759  0.261  1.0
  O  O37  1  0.829  0.581  0.677  1.0
  O  O38  1  0.481  0.241  0.239  1.0
  O  O39  1  0.019  0.241  0.739  1.0
  O  O40  1  0.433  0.888  0.300  1.0
  O  O41  1  0.067  0.888  0.800  1.0
  O  O42  1  0.567  0.112  0.700  1.0
  O  O43  1  0.519  0.759  0.761  1.0
[/CIF]
.
The structure described by Na4Fe2O5 crystallizes in the monoclinic P2_1/c space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a 5-coordinate geometry to one O(1), one O(4), one O(5), and two equivalent O(3) atoms. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(5), and two equivalent O(4) atoms. In the third Na site, Na(3) is bonded to one O(2), one O(3), one O(5), and two equivalent O(4) atoms to form distorted NaO5 trigonal bipyramids that share  a cornercorner with one Fe(2)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Na(4)O5 trigonal bipyramids, edges with two equivalent Fe(2)O4 tetrahedra,  an edgeedge with one Na(3)O5 trigonal bipyramid, and  an edgeedge with one Na(4)O5 trigonal bipyramid. In the fourth Na site, Na(4) is bonded to one O(1), one O(2), one O(5), and two equivalent O(3) atoms to form distorted NaO5 trigonal bipyramids that share  a cornercorner with one Fe(2)O4 tetrahedra, corners with three equivalent Fe(1)O4 tetrahedra, corners with two equivalent Na(3)O5 trigonal bipyramids,  an edgeedge with one Fe(1)O4 tetrahedra,  an edgeedge with one Fe(2)O4 tetrahedra,  an edgeedge with one Na(3)O5 trigonal bipyramid, and  an edgeedge with one Na(4)O5 trigonal bipyramid. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), one O(5), and two equivalent O(1) atoms to form FeO4 tetrahedra that share  a cornercorner with one Fe(2)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Na(3)O5 trigonal bipyramids, corners with three equivalent Na(4)O5 trigonal bipyramids, and  an edgeedge with one Na(4)O5 trigonal bipyramid. In the second Fe site, Fe(2) is bonded to one O(4), one O(5), and two equivalent O(2) atoms to form FeO4 tetrahedra that share  a cornercorner with one Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra,  a cornercorner with one Na(3)O5 trigonal bipyramid,  a cornercorner with one Na(4)O5 trigonal bipyramid,  an edgeedge with one Na(4)O5 trigonal bipyramid, and edges with two equivalent Na(3)O5 trigonal bipyramids. There are five inequivalent O sites. In the first O site, O(4) is bonded to one Na(1), two equivalent Na(2), two equivalent Na(3), and one Fe(2) atom to form a mixture of distorted edge and corner-sharing ONa5Fe octahedra. The corner-sharing octahedral tilt angles range from 42-52°. In the second O site, O(5) is bonded in a 6-coordinate geometry to one Na(1), one Na(2), one Na(3), one Na(4), one Fe(1), and one Fe(2) atom. In the third O site, O(1) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(4), and two equivalent Fe(1) atoms. In the fourth O site, O(2) is bonded in a 5-coordinate geometry to one Na(2), one Na(3), one Na(4), and two equivalent Fe(2) atoms. In the fifth O site, O(3) is bonded to one Na(3), two equivalent Na(1), two equivalent Na(4), and one Fe(1) atom to form a mixture of edge and corner-sharing ONa5Fe octahedra. The corner-sharing octahedral tilt angles range from 42-52°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na4Fe2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.773
_cell_length_b   9.254
_cell_length_c   13.127
_cell_angle_alpha   62.066
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   619.549
_cell_formula_units_Z   4
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  0.927  0.194  0.967  1.0
  Na  Na1  1  0.427  0.806  0.533  1.0
  Na  Na2  1  0.114  0.606  0.878  1.0
  Na  Na3  1  0.573  0.194  0.467  1.0
  Na  Na4  1  0.411  0.298  0.038  1.0
  Na  Na5  1  0.911  0.702  0.462  1.0
  Na  Na6  1  0.589  0.702  0.962  1.0
  Na  Na7  1  0.089  0.298  0.538  1.0
  Na  Na8  1  0.619  0.870  0.133  1.0
  Na  Na9  1  0.119  0.130  0.367  1.0
  Na  Na10  1  0.381  0.130  0.867  1.0
  Na  Na11  1  0.881  0.870  0.633  1.0
  Na  Na12  1  0.386  0.606  0.378  1.0
  Na  Na13  1  0.886  0.394  0.122  1.0
  Na  Na14  1  0.614  0.394  0.622  1.0
  Na  Na15  1  0.073  0.806  0.033  1.0
  Fe  Fe16  1  0.658  0.044  0.297  1.0
  Fe  Fe17  1  0.342  0.956  0.703  1.0
  Fe  Fe18  1  0.842  0.044  0.797  1.0
  Fe  Fe19  1  0.615  0.543  0.801  1.0
  Fe  Fe20  1  0.115  0.457  0.699  1.0
  Fe  Fe21  1  0.385  0.457  0.199  1.0
  Fe  Fe22  1  0.885  0.543  0.301  1.0
  Fe  Fe23  1  0.158  0.956  0.203  1.0
  O  O24  1  0.933  0.112  0.200  1.0
  O  O25  1  0.329  0.419  0.823  1.0
  O  O26  1  0.171  0.419  0.323  1.0
  O  O27  1  0.671  0.581  0.177  1.0
  O  O28  1  0.260  0.031  0.053  1.0
  O  O29  1  0.760  0.969  0.447  1.0
  O  O30  1  0.740  0.969  0.947  1.0
  O  O31  1  0.240  0.031  0.553  1.0
  O  O32  1  0.761  0.447  0.943  1.0
  O  O33  1  0.261  0.553  0.557  1.0
  O  O34  1  0.239  0.553  0.057  1.0
  O  O35  1  0.739  0.447  0.443  1.0
  O  O36  1  0.981  0.759  0.261  1.0
  O  O37  1  0.829  0.581  0.677  1.0
  O  O38  1  0.481  0.241  0.239  1.0
  O  O39  1  0.019  0.241  0.739  1.0
  O  O40  1  0.433  0.888  0.300  1.0
  O  O41  1  0.067  0.888  0.800  1.0
  O  O42  1  0.567  0.112  0.700  1.0
  O  O43  1  0.519  0.759  0.761  1.0
[/CIF]
.