The compound described by MgFe4(OF)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(3), two equivalent O(1), one F(2), and two equivalent F(4) atoms to form distorted MgO3F3 octahedra that share  a cornercorner with one Fe(2)O2F2 tetrahedra, edges with two equivalent Mg(1)O3F3 octahedra, and edges with four equivalent Fe(4)O3F3 octahedra. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 6-coordinate geometry to one O(2), two equivalent O(1), one F(2), and two equivalent F(3) atoms. In the second Fe site, Fe(2) is bonded to one O(3), one O(4), and two equivalent F(1) atoms to form FeO2F2 tetrahedra that share  a cornercorner with one Mg(1)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, corners with four equivalent Fe(3)O4F2 octahedra, and corners with two equivalent Fe(2)O2F2 tetrahedra. The corner-sharing octahedral tilt angles range from 46-64°. In the third Fe site, Fe(3) is bonded to two equivalent O(2), two equivalent O(4), one F(1), and one F(3) atom to form FeO4F2 octahedra that share corners with four equivalent Fe(2)O2F2 tetrahedra and edges with two equivalent Fe(3)O4F2 octahedra. In the fourth Fe site, Fe(4) is bonded to one O(1), two equivalent O(3), one F(4), and two equivalent F(2) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(2)O2F2 tetrahedra, edges with two equivalent Fe(4)O3F3 octahedra, and edges with four equivalent Mg(1)O3F3 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1), one Fe(4), and two equivalent Fe(1) atoms to form distorted OMg2Fe3 trigonal bipyramids that share edges with two equivalent O(1)Mg2Fe3 trigonal bipyramids and edges with two equivalent O(3)MgFe3 trigonal pyramids. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(1) and two equivalent Fe(3) atoms. In the third O site, O(3) is bonded to one Mg(1), one Fe(2), and two equivalent Fe(4) atoms to form distorted OMgFe3 trigonal pyramids that share corners with two equivalent O(3)MgFe3 trigonal pyramids and edges with two equivalent O(1)Mg2Fe3 trigonal bipyramids. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Fe(3) atoms. There are four inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to one Fe(3) and two equivalent Fe(2) atoms. In the second F site, F(2) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(1), and two equivalent Fe(4) atoms. In the third F site, F(3) is bonded in a 3-coordinate geometry to one Fe(3) and two equivalent Fe(1) atoms. In the fourth F site, F(4) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Mg(1) and one Fe(4) atom. is represented by the CIF card [CIF]
data_MgFe4(OF)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.382
_cell_length_b   10.060
_cell_length_c   3.029
_cell_angle_alpha   90.460
_cell_angle_beta   90.434
_cell_angle_gamma   101.753
_symmetry_Int_Tables_number   1
_cell_volume   160.565
_cell_formula_units_Z   1
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
  Mg  Mg0  1  0.884  0.737  0.979  1.0
  Fe  Fe1  1  0.064  0.022  0.985  1.0
  Fe  Fe2  1  0.112  0.454  0.994  1.0
  Fe  Fe3  1  0.575  0.250  0.492  1.0
  Fe  Fe4  1  0.379  0.765  0.481  1.0
  O  O5  1  0.084  0.889  0.482  1.0
  O  O6  1  0.380  0.141  0.987  1.0
  O  O7  1  0.182  0.651  0.993  1.0
  O  O8  1  0.776  0.336  0.996  1.0
  F  F9  1  0.325  0.381  0.495  1.0
  F  F10  1  0.635  0.867  0.968  1.0
  F  F11  1  0.890  0.108  0.485  1.0
  F  F12  1  0.687  0.650  0.475  1.0
[/CIF]
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The compound described by MgFe4(OF)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(3), two equivalent O(1), one F(2), and two equivalent F(4) atoms to form distorted MgO3F3 octahedra that share  a cornercorner with one Fe(2)O2F2 tetrahedra, edges with two equivalent Mg(1)O3F3 octahedra, and edges with four equivalent Fe(4)O3F3 octahedra. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 6-coordinate geometry to one O(2), two equivalent O(1), one F(2), and two equivalent F(3) atoms. In the second Fe site, Fe(2) is bonded to one O(3), one O(4), and two equivalent F(1) atoms to form FeO2F2 tetrahedra that share  a cornercorner with one Mg(1)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, corners with four equivalent Fe(3)O4F2 octahedra, and corners with two equivalent Fe(2)O2F2 tetrahedra. The corner-sharing octahedral tilt angles range from 46-64°. In the third Fe site, Fe(3) is bonded to two equivalent O(2), two equivalent O(4), one F(1), and one F(3) atom to form FeO4F2 octahedra that share corners with four equivalent Fe(2)O2F2 tetrahedra and edges with two equivalent Fe(3)O4F2 octahedra. In the fourth Fe site, Fe(4) is bonded to one O(1), two equivalent O(3), one F(4), and two equivalent F(2) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(2)O2F2 tetrahedra, edges with two equivalent Fe(4)O3F3 octahedra, and edges with four equivalent Mg(1)O3F3 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1), one Fe(4), and two equivalent Fe(1) atoms to form distorted OMg2Fe3 trigonal bipyramids that share edges with two equivalent O(1)Mg2Fe3 trigonal bipyramids and edges with two equivalent O(3)MgFe3 trigonal pyramids. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(1) and two equivalent Fe(3) atoms. In the third O site, O(3) is bonded to one Mg(1), one Fe(2), and two equivalent Fe(4) atoms to form distorted OMgFe3 trigonal pyramids that share corners with two equivalent O(3)MgFe3 trigonal pyramids and edges with two equivalent O(1)Mg2Fe3 trigonal bipyramids. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Fe(3) atoms. There are four inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to one Fe(3) and two equivalent Fe(2) atoms. In the second F site, F(2) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(1), and two equivalent Fe(4) atoms. In the third F site, F(3) is bonded in a 3-coordinate geometry to one Fe(3) and two equivalent Fe(1) atoms. In the fourth F site, F(4) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Mg(1) and one Fe(4) atom. is represented by the CIF card [CIF]
data_MgFe4(OF)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.382
_cell_length_b   10.060
_cell_length_c   3.029
_cell_angle_alpha   90.460
_cell_angle_beta   90.434
_cell_angle_gamma   101.753
_symmetry_Int_Tables_number   1
_cell_volume   160.565
_cell_formula_units_Z   1
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
  Mg  Mg0  1  0.884  0.737  0.979  1.0
  Fe  Fe1  1  0.064  0.022  0.985  1.0
  Fe  Fe2  1  0.112  0.454  0.994  1.0
  Fe  Fe3  1  0.575  0.250  0.492  1.0
  Fe  Fe4  1  0.379  0.765  0.481  1.0
  O  O5  1  0.084  0.889  0.482  1.0
  O  O6  1  0.380  0.141  0.987  1.0
  O  O7  1  0.182  0.651  0.993  1.0
  O  O8  1  0.776  0.336  0.996  1.0
  F  F9  1  0.325  0.381  0.495  1.0
  F  F10  1  0.635  0.867  0.968  1.0
  F  F11  1  0.890  0.108  0.485  1.0
  F  F12  1  0.687  0.650  0.475  1.0
[/CIF]
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