The crystal structure described by Na2NiFeF7 crystallizes in the orthorhombic Imma space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent F(2), two equivalent F(3), and four equivalent F(1) atoms to form distorted NaF8 hexagonal bipyramids that share corners with two equivalent Na(1)F8 hexagonal bipyramids, corners with two equivalent Fe(1)F6 octahedra, edges with two equivalent Fe(1)F6 octahedra, and edges with four equivalent Ni(1)F6 octahedra. The corner-sharing octahedral tilt angles are 54°. In the second Na site, Na(2) is bonded in a distorted body-centered cubic geometry to four equivalent F(1) and four equivalent F(3) atoms. Fe(1) is bonded to two equivalent F(3) and four equivalent F(1) atoms to form FeF6 octahedra that share corners with two equivalent Na(1)F8 hexagonal bipyramids, corners with four equivalent Ni(1)F6 octahedra, and edges with two equivalent Na(1)F8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 43°. Ni(1) is bonded to two equivalent F(2) and four equivalent F(1) atoms to form NiF6 octahedra that share corners with two equivalent Ni(1)F6 octahedra, corners with four equivalent Fe(1)F6 octahedra, and edges with four equivalent Na(1)F8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 43-46°. There are three inequivalent F sites. In the first F site, F(1) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Fe(1), and one Ni(1) atom. In the second F site, F(2) is bonded in a 2-coordinate geometry to two equivalent Na(1) and two equivalent Ni(1) atoms. In the third F site, F(3) is bonded to one Na(1), two equivalent Na(2), and one Fe(1) atom to form a mixture of distorted edge and corner-sharing FNa3Fe tetrahedra. is represented by the CIF file [CIF]
data_Na2FeNiF7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.397
_cell_length_b   7.397
_cell_length_c   7.397
_cell_angle_alpha   120.921
_cell_angle_beta   118.602
_cell_angle_gamma   90.425
_symmetry_Int_Tables_number   1
_cell_volume   287.040
_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  0.500  0.500  0.000  1.0
  Na  Na1  1  0.000  0.000  0.000  1.0
  Na  Na2  1  0.500  0.000  0.000  1.0
  Na  Na3  1  0.500  0.500  0.500  1.0
  Fe  Fe4  1  0.000  0.500  0.500  1.0
  Fe  Fe5  1  0.500  0.000  0.500  1.0
  Ni  Ni6  1  0.000  0.000  0.500  1.0
  Ni  Ni7  1  0.000  0.500  0.000  1.0
  F  F8  1  0.947  0.584  0.763  1.0
  F  F9  1  0.053  0.816  0.637  1.0
  F  F10  1  0.679  0.916  0.363  1.0
  F  F11  1  0.321  0.684  0.237  1.0
  F  F12  1  0.053  0.416  0.237  1.0
  F  F13  1  0.947  0.184  0.363  1.0
  F  F14  1  0.321  0.084  0.637  1.0
  F  F15  1  0.679  0.316  0.763  1.0
  F  F16  1  0.103  0.250  0.853  1.0
  F  F17  1  0.897  0.750  0.147  1.0
  F  F18  1  0.361  0.091  0.270  1.0
  F  F19  1  0.639  0.909  0.730  1.0
  F  F20  1  0.679  0.409  0.270  1.0
  F  F21  1  0.321  0.591  0.730  1.0
[/CIF]
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The crystal structure described by Na2NiFeF7 crystallizes in the orthorhombic Imma space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent F(2), two equivalent F(3), and four equivalent F(1) atoms to form distorted NaF8 hexagonal bipyramids that share corners with two equivalent Na(1)F8 hexagonal bipyramids, corners with two equivalent Fe(1)F6 octahedra, edges with two equivalent Fe(1)F6 octahedra, and edges with four equivalent Ni(1)F6 octahedra. The corner-sharing octahedral tilt angles are 54°. In the second Na site, Na(2) is bonded in a distorted body-centered cubic geometry to four equivalent F(1) and four equivalent F(3) atoms. Fe(1) is bonded to two equivalent F(3) and four equivalent F(1) atoms to form FeF6 octahedra that share corners with two equivalent Na(1)F8 hexagonal bipyramids, corners with four equivalent Ni(1)F6 octahedra, and edges with two equivalent Na(1)F8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 43°. Ni(1) is bonded to two equivalent F(2) and four equivalent F(1) atoms to form NiF6 octahedra that share corners with two equivalent Ni(1)F6 octahedra, corners with four equivalent Fe(1)F6 octahedra, and edges with four equivalent Na(1)F8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 43-46°. There are three inequivalent F sites. In the first F site, F(1) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Fe(1), and one Ni(1) atom. In the second F site, F(2) is bonded in a 2-coordinate geometry to two equivalent Na(1) and two equivalent Ni(1) atoms. In the third F site, F(3) is bonded to one Na(1), two equivalent Na(2), and one Fe(1) atom to form a mixture of distorted edge and corner-sharing FNa3Fe tetrahedra. is represented by the CIF file [CIF]
data_Na2FeNiF7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.397
_cell_length_b   7.397
_cell_length_c   7.397
_cell_angle_alpha   120.921
_cell_angle_beta   118.602
_cell_angle_gamma   90.425
_symmetry_Int_Tables_number   1
_cell_volume   287.040
_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  0.500  0.500  0.000  1.0
  Na  Na1  1  0.000  0.000  0.000  1.0
  Na  Na2  1  0.500  0.000  0.000  1.0
  Na  Na3  1  0.500  0.500  0.500  1.0
  Fe  Fe4  1  0.000  0.500  0.500  1.0
  Fe  Fe5  1  0.500  0.000  0.500  1.0
  Ni  Ni6  1  0.000  0.000  0.500  1.0
  Ni  Ni7  1  0.000  0.500  0.000  1.0
  F  F8  1  0.947  0.584  0.763  1.0
  F  F9  1  0.053  0.816  0.637  1.0
  F  F10  1  0.679  0.916  0.363  1.0
  F  F11  1  0.321  0.684  0.237  1.0
  F  F12  1  0.053  0.416  0.237  1.0
  F  F13  1  0.947  0.184  0.363  1.0
  F  F14  1  0.321  0.084  0.637  1.0
  F  F15  1  0.679  0.316  0.763  1.0
  F  F16  1  0.103  0.250  0.853  1.0
  F  F17  1  0.897  0.750  0.147  1.0
  F  F18  1  0.361  0.091  0.270  1.0
  F  F19  1  0.639  0.909  0.730  1.0
  F  F20  1  0.679  0.409  0.270  1.0
  F  F21  1  0.321  0.591  0.730  1.0
[/CIF]
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