The crystal structure described by NH4Fe2F6 is Upper Bainite-derived structured and crystallizes in the orthorhombic Pnma space group. The structure consists of four ammonium molecules inside a FeF3 framework. In the FeF3 framework, there are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent F(2), two equivalent F(3), and two equivalent F(4) atoms to form corner-sharing FeF6 octahedra. The corner-sharing octahedral tilt angles range from 34-55°. In the second Fe site, Fe(2) is bonded to two equivalent F(1), two equivalent F(2), and two equivalent F(4) atoms to form corner-sharing FeF6 octahedra. The corner-sharing octahedral tilt angles range from 49-56°. There are four inequivalent F sites. In the first F site, F(2) is bonded in a bent 120 degrees geometry to one Fe(1) and one Fe(2) atom. In the second F site, F(3) is bonded in a bent 150 degrees geometry to two equivalent Fe(1) atoms. In the third F site, F(4) is bonded in a bent 120 degrees geometry to one Fe(1) and one Fe(2) atom. In the fourth F site, F(1) is bonded in a bent 120 degrees geometry to two equivalent Fe(2) atoms. is represented by the CIF file [CIF]
data_Fe2H4NF6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.267
_cell_length_b   7.573
_cell_length_c   10.160
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   559.161
_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
  Fe  Fe0  1  0.000  0.000  0.000  1.0
  Fe  Fe1  1  0.500  0.000  0.500  1.0
  Fe  Fe2  1  0.000  0.500  0.000  1.0
  Fe  Fe3  1  0.500  0.500  0.500  1.0
  Fe  Fe4  1  0.209  0.250  0.267  1.0
  Fe  Fe5  1  0.791  0.750  0.733  1.0
  Fe  Fe6  1  0.291  0.750  0.767  1.0
  Fe  Fe7  1  0.709  0.250  0.233  1.0
  H  H8  1  0.142  0.250  0.627  1.0
  H  H9  1  0.858  0.750  0.373  1.0
  H  H10  1  0.358  0.750  0.127  1.0
  H  H11  1  0.642  0.250  0.873  1.0
  H  H12  1  0.052  0.639  0.336  1.0
  H  H13  1  0.948  0.361  0.664  1.0
  H  H14  1  0.448  0.361  0.836  1.0
  H  H15  1  0.948  0.139  0.664  1.0
  H  H16  1  0.552  0.639  0.164  1.0
  H  H17  1  0.052  0.861  0.336  1.0
  H  H18  1  0.552  0.861  0.164  1.0
  H  H19  1  0.448  0.139  0.836  1.0
  H  H20  1  0.467  0.250  0.982  1.0
  H  H21  1  0.533  0.750  0.018  1.0
  H  H22  1  0.033  0.750  0.482  1.0
  H  H23  1  0.967  0.250  0.518  1.0
  N  N24  1  0.001  0.250  0.618  1.0
  N  N25  1  0.999  0.750  0.382  1.0
  N  N26  1  0.499  0.750  0.118  1.0
  N  N27  1  0.501  0.250  0.882  1.0
  F  F28  1  0.440  0.250  0.155  1.0
  F  F29  1  0.560  0.750  0.845  1.0
  F  F30  1  0.060  0.750  0.655  1.0
  F  F31  1  0.940  0.250  0.345  1.0
  F  F32  1  0.268  0.062  0.416  1.0
  F  F33  1  0.732  0.938  0.584  1.0
  F  F34  1  0.232  0.938  0.916  1.0
  F  F35  1  0.732  0.562  0.584  1.0
  F  F36  1  0.768  0.062  0.084  1.0
  F  F37  1  0.268  0.438  0.416  1.0
  F  F38  1  0.768  0.438  0.084  1.0
  F  F39  1  0.232  0.562  0.916  1.0
  F  F40  1  0.561  0.250  0.536  1.0
  F  F41  1  0.439  0.750  0.464  1.0
  F  F42  1  0.939  0.750  0.036  1.0
  F  F43  1  0.061  0.250  0.964  1.0
  F  F44  1  0.128  0.489  0.169  1.0
  F  F45  1  0.872  0.511  0.831  1.0
  F  F46  1  0.372  0.511  0.669  1.0
  F  F47  1  0.872  0.989  0.831  1.0
  F  F48  1  0.628  0.489  0.331  1.0
  F  F49  1  0.128  0.011  0.169  1.0
  F  F50  1  0.628  0.011  0.331  1.0
  F  F51  1  0.372  0.989  0.669  1.0
[/CIF]
.
The crystal structure described by NH4Fe2F6 is Upper Bainite-derived structured and crystallizes in the orthorhombic Pnma space group. The structure consists of four ammonium molecules inside a FeF3 framework. In the FeF3 framework, there are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent F(2), two equivalent F(3), and two equivalent F(4) atoms to form corner-sharing FeF6 octahedra. The corner-sharing octahedral tilt angles range from 34-55°. In the second Fe site, Fe(2) is bonded to two equivalent F(1), two equivalent F(2), and two equivalent F(4) atoms to form corner-sharing FeF6 octahedra. The corner-sharing octahedral tilt angles range from 49-56°. There are four inequivalent F sites. In the first F site, F(2) is bonded in a bent 120 degrees geometry to one Fe(1) and one Fe(2) atom. In the second F site, F(3) is bonded in a bent 150 degrees geometry to two equivalent Fe(1) atoms. In the third F site, F(4) is bonded in a bent 120 degrees geometry to one Fe(1) and one Fe(2) atom. In the fourth F site, F(1) is bonded in a bent 120 degrees geometry to two equivalent Fe(2) atoms. is represented by the CIF file [CIF]
data_Fe2H4NF6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.267
_cell_length_b   7.573
_cell_length_c   10.160
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   559.161
_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
  Fe  Fe0  1  0.000  0.000  0.000  1.0
  Fe  Fe1  1  0.500  0.000  0.500  1.0
  Fe  Fe2  1  0.000  0.500  0.000  1.0
  Fe  Fe3  1  0.500  0.500  0.500  1.0
  Fe  Fe4  1  0.209  0.250  0.267  1.0
  Fe  Fe5  1  0.791  0.750  0.733  1.0
  Fe  Fe6  1  0.291  0.750  0.767  1.0
  Fe  Fe7  1  0.709  0.250  0.233  1.0
  H  H8  1  0.142  0.250  0.627  1.0
  H  H9  1  0.858  0.750  0.373  1.0
  H  H10  1  0.358  0.750  0.127  1.0
  H  H11  1  0.642  0.250  0.873  1.0
  H  H12  1  0.052  0.639  0.336  1.0
  H  H13  1  0.948  0.361  0.664  1.0
  H  H14  1  0.448  0.361  0.836  1.0
  H  H15  1  0.948  0.139  0.664  1.0
  H  H16  1  0.552  0.639  0.164  1.0
  H  H17  1  0.052  0.861  0.336  1.0
  H  H18  1  0.552  0.861  0.164  1.0
  H  H19  1  0.448  0.139  0.836  1.0
  H  H20  1  0.467  0.250  0.982  1.0
  H  H21  1  0.533  0.750  0.018  1.0
  H  H22  1  0.033  0.750  0.482  1.0
  H  H23  1  0.967  0.250  0.518  1.0
  N  N24  1  0.001  0.250  0.618  1.0
  N  N25  1  0.999  0.750  0.382  1.0
  N  N26  1  0.499  0.750  0.118  1.0
  N  N27  1  0.501  0.250  0.882  1.0
  F  F28  1  0.440  0.250  0.155  1.0
  F  F29  1  0.560  0.750  0.845  1.0
  F  F30  1  0.060  0.750  0.655  1.0
  F  F31  1  0.940  0.250  0.345  1.0
  F  F32  1  0.268  0.062  0.416  1.0
  F  F33  1  0.732  0.938  0.584  1.0
  F  F34  1  0.232  0.938  0.916  1.0
  F  F35  1  0.732  0.562  0.584  1.0
  F  F36  1  0.768  0.062  0.084  1.0
  F  F37  1  0.268  0.438  0.416  1.0
  F  F38  1  0.768  0.438  0.084  1.0
  F  F39  1  0.232  0.562  0.916  1.0
  F  F40  1  0.561  0.250  0.536  1.0
  F  F41  1  0.439  0.750  0.464  1.0
  F  F42  1  0.939  0.750  0.036  1.0
  F  F43  1  0.061  0.250  0.964  1.0
  F  F44  1  0.128  0.489  0.169  1.0
  F  F45  1  0.872  0.511  0.831  1.0
  F  F46  1  0.372  0.511  0.669  1.0
  F  F47  1  0.872  0.989  0.831  1.0
  F  F48  1  0.628  0.489  0.331  1.0
  F  F49  1  0.128  0.011  0.169  1.0
  F  F50  1  0.628  0.011  0.331  1.0
  F  F51  1  0.372  0.989  0.669  1.0
[/CIF]
.