The compound described by MgFe4(OF)4 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(2), two equivalent O(1), one F(2), and two equivalent F(3) atoms to form MgO3F3 octahedra that share corners with four equivalent Fe(1)O3F3 octahedra, corners with two equivalent Fe(3)O4F square pyramids, edges with two equivalent Mg(1)O3F3 octahedra, edges with two equivalent Fe(4)O3F3 octahedra, and faces with two equivalent Fe(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 40-43°. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), two equivalent O(1), one F(2), and two equivalent F(3) atoms to form distorted FeO3F3 octahedra that share corners with four equivalent Mg(1)O3F3 octahedra, corners with four equivalent Fe(4)O3F3 octahedra, corners with two equivalent Fe(3)O4F square pyramids, edges with two equivalent Fe(1)O3F3 octahedra, and faces with two equivalent Mg(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 39-58°. In the second Fe site, Fe(2) is bonded to one O(3), one O(4), two equivalent F(1), and two equivalent F(4) atoms to form FeO2F4 octahedra that share corners with four equivalent Fe(4)O3F3 octahedra, corners with four equivalent Fe(3)O4F square pyramids, and edges with two equivalent Fe(2)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 50-51°. In the third Fe site, Fe(3) is bonded to two equivalent O(2), two equivalent O(4), and one F(1) atom to form FeO4F square pyramids that share corners with two equivalent Mg(1)O3F3 octahedra, corners with two equivalent Fe(1)O3F3 octahedra, corners with four equivalent Fe(2)O2F4 octahedra, and edges with two equivalent Fe(3)O4F square pyramids. The corner-sharing octahedral tilt angles range from 49-70°. 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 distorted FeO3F3 octahedra that share corners with four equivalent Fe(2)O2F4 octahedra, corners with four equivalent Fe(1)O3F3 octahedra, edges with two equivalent Mg(1)O3F3 octahedra, and edges with two equivalent Fe(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 39-58°. 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(2)MgFe3 tetrahedra and edges with two equivalent O(1)Mg2Fe3 trigonal bipyramids. In the second O site, O(2) is bonded to one Mg(1), one Fe(1), and two equivalent Fe(3) atoms to form OMgFe3 tetrahedra that share corners with two equivalent O(2)MgFe3 tetrahedra and edges with two equivalent O(1)Mg2Fe3 trigonal bipyramids. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(2) and two equivalent Fe(4) atoms. 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 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 4-coordinate geometry to two equivalent Mg(1) and two equivalent Fe(1) atoms. In the fourth F site, F(4) is bonded in a distorted trigonal planar geometry to one Fe(4) and two equivalent Fe(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgFe4(OF)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.218
_cell_length_b   9.970
_cell_length_c   3.061
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   96.920
_symmetry_Int_Tables_number   1
_cell_volume   158.061
_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  0.566  0.008  0.000  1.0
  Fe  Fe1  1  0.087  0.985  0.000  1.0
  Fe  Fe2  1  0.963  0.510  0.000  1.0
  Fe  Fe3  1  0.449  0.293  0.500  1.0
  Fe  Fe4  1  0.441  0.729  0.500  1.0
  O  O5  1  0.326  0.919  0.500  1.0
  O  O6  1  0.343  0.163  0.000  1.0
  O  O7  1  0.266  0.625  0.000  1.0
  O  O8  1  0.650  0.377  0.000  1.0
  F  F9  1  0.122  0.390  0.500  1.0
  F  F10  1  0.754  0.845  0.000  1.0
  F  F11  1  0.818  0.073  0.500  1.0
  F  F12  1  0.799  0.603  0.500  1.0
[/CIF]
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The compound described by MgFe4(OF)4 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(2), two equivalent O(1), one F(2), and two equivalent F(3) atoms to form MgO3F3 octahedra that share corners with four equivalent Fe(1)O3F3 octahedra, corners with two equivalent Fe(3)O4F square pyramids, edges with two equivalent Mg(1)O3F3 octahedra, edges with two equivalent Fe(4)O3F3 octahedra, and faces with two equivalent Fe(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 40-43°. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), two equivalent O(1), one F(2), and two equivalent F(3) atoms to form distorted FeO3F3 octahedra that share corners with four equivalent Mg(1)O3F3 octahedra, corners with four equivalent Fe(4)O3F3 octahedra, corners with two equivalent Fe(3)O4F square pyramids, edges with two equivalent Fe(1)O3F3 octahedra, and faces with two equivalent Mg(1)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 39-58°. In the second Fe site, Fe(2) is bonded to one O(3), one O(4), two equivalent F(1), and two equivalent F(4) atoms to form FeO2F4 octahedra that share corners with four equivalent Fe(4)O3F3 octahedra, corners with four equivalent Fe(3)O4F square pyramids, and edges with two equivalent Fe(2)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 50-51°. In the third Fe site, Fe(3) is bonded to two equivalent O(2), two equivalent O(4), and one F(1) atom to form FeO4F square pyramids that share corners with two equivalent Mg(1)O3F3 octahedra, corners with two equivalent Fe(1)O3F3 octahedra, corners with four equivalent Fe(2)O2F4 octahedra, and edges with two equivalent Fe(3)O4F square pyramids. The corner-sharing octahedral tilt angles range from 49-70°. 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 distorted FeO3F3 octahedra that share corners with four equivalent Fe(2)O2F4 octahedra, corners with four equivalent Fe(1)O3F3 octahedra, edges with two equivalent Mg(1)O3F3 octahedra, and edges with two equivalent Fe(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 39-58°. 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(2)MgFe3 tetrahedra and edges with two equivalent O(1)Mg2Fe3 trigonal bipyramids. In the second O site, O(2) is bonded to one Mg(1), one Fe(1), and two equivalent Fe(3) atoms to form OMgFe3 tetrahedra that share corners with two equivalent O(2)MgFe3 tetrahedra and edges with two equivalent O(1)Mg2Fe3 trigonal bipyramids. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(2) and two equivalent Fe(4) atoms. 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 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 4-coordinate geometry to two equivalent Mg(1) and two equivalent Fe(1) atoms. In the fourth F site, F(4) is bonded in a distorted trigonal planar geometry to one Fe(4) and two equivalent Fe(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgFe4(OF)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.218
_cell_length_b   9.970
_cell_length_c   3.061
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   96.920
_symmetry_Int_Tables_number   1
_cell_volume   158.061
_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  0.566  0.008  0.000  1.0
  Fe  Fe1  1  0.087  0.985  0.000  1.0
  Fe  Fe2  1  0.963  0.510  0.000  1.0
  Fe  Fe3  1  0.449  0.293  0.500  1.0
  Fe  Fe4  1  0.441  0.729  0.500  1.0
  O  O5  1  0.326  0.919  0.500  1.0
  O  O6  1  0.343  0.163  0.000  1.0
  O  O7  1  0.266  0.625  0.000  1.0
  O  O8  1  0.650  0.377  0.000  1.0
  F  F9  1  0.122  0.390  0.500  1.0
  F  F10  1  0.754  0.845  0.000  1.0
  F  F11  1  0.818  0.073  0.500  1.0
  F  F12  1  0.799  0.603  0.500  1.0
[/CIF]
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