The material described by MgFe4(OF)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(2), one F(1), one F(2), one F(3), and one F(4) atom to form MgO2F4 octahedra that share corners with two equivalent Fe(2)O4F3 pentagonal bipyramids, corners with two equivalent Fe(4)O4F3 pentagonal bipyramids, edges with two equivalent Fe(3)O3F3 octahedra,  a faceface with one Fe(2)O4F3 pentagonal bipyramid, and  a faceface with one Fe(4)O4F3 pentagonal bipyramid. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(4), one F(1), one F(2), and one F(4) atom. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), one O(4), one F(2), one F(3), and one F(4) atom to form distorted FeO4F3 pentagonal bipyramids that share corners with two equivalent Mg(1)O2F4 octahedra, corners with three equivalent Fe(3)O3F3 octahedra,  an edgeedge with one Fe(3)O3F3 octahedra, edges with three equivalent Fe(4)O4F3 pentagonal bipyramids, and  a faceface with one Mg(1)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 22-68°. In the third Fe site, Fe(3) is bonded to one O(2), one O(3), one O(4), one F(1), one F(2), and one F(3) atom to form FeO3F3 octahedra that share corners with three equivalent Fe(2)O4F3 pentagonal bipyramids, corners with three equivalent Fe(4)O4F3 pentagonal bipyramids, edges with two equivalent Mg(1)O2F4 octahedra,  an edgeedge with one Fe(2)O4F3 pentagonal bipyramid, and  an edgeedge with one Fe(4)O4F3 pentagonal bipyramid. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(2), one O(3), one O(4), one F(1), one F(3), and one F(4) atom to form distorted FeO4F3 pentagonal bipyramids that share corners with two equivalent Mg(1)O2F4 octahedra, corners with three equivalent Fe(3)O3F3 octahedra,  an edgeedge with one Fe(3)O3F3 octahedra, edges with three equivalent Fe(2)O4F3 pentagonal bipyramids, and  a faceface with one Mg(1)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 40-61°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Fe(1), one Fe(2), and one Fe(4) atom to form distorted OMgFe3 trigonal pyramids that share corners with three equivalent O(3)Fe4 tetrahedra,  a cornercorner with one O(4)Fe4 trigonal pyramid,  a cornercorner with one F(2)MgFe3 trigonal pyramid, corners with three equivalent O(2)MgFe3 trigonal pyramids,  an edgeedge with one O(4)Fe4 trigonal pyramid, and  an edgeedge with one F(2)MgFe3 trigonal pyramid. In the second O site, O(2) is bonded to one Mg(1), one Fe(2), one Fe(3), and one Fe(4) atom to form distorted OMgFe3 trigonal pyramids that share  a cornercorner with one O(3)Fe4 tetrahedra,  a cornercorner with one F(2)MgFe3 trigonal pyramid, corners with three equivalent O(4)Fe4 trigonal pyramids, corners with three equivalent O(1)MgFe3 trigonal pyramids,  an edgeedge with one O(3)Fe4 tetrahedra, and  an edgeedge with one F(2)MgFe3 trigonal pyramid. In the third O site, O(3) is bonded to one Fe(1), one Fe(2), one Fe(3), and one Fe(4) atom to form OFe4 tetrahedra that share  a cornercorner with one O(2)MgFe3 trigonal pyramid, corners with two equivalent O(4)Fe4 trigonal pyramids, corners with three equivalent O(1)MgFe3 trigonal pyramids, corners with three equivalent F(2)MgFe3 trigonal pyramids,  an edgeedge with one O(4)Fe4 trigonal pyramid, and  an edgeedge with one O(2)MgFe3 trigonal pyramid. In the fourth O site, O(4) is bonded to one Fe(1), one Fe(2), one Fe(3), and one Fe(4) atom to form distorted OFe4 trigonal pyramids that share corners with two equivalent O(3)Fe4 tetrahedra,  a cornercorner with one O(1)MgFe3 trigonal pyramid,  a cornercorner with one F(2)MgFe3 trigonal pyramid, corners with three equivalent O(2)MgFe3 trigonal pyramids,  an edgeedge with one O(3)Fe4 tetrahedra,  an edgeedge with one O(1)MgFe3 trigonal pyramid, and  an edgeedge with one F(2)MgFe3 trigonal pyramid. There are four inequivalent F sites. In the first F site, F(1) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(1), one Fe(3), and one Fe(4) atom. In the second F site, F(2) is bonded to one Mg(1), one Fe(1), one Fe(2), and one Fe(3) atom to form distorted FMgFe3 trigonal pyramids that share corners with three equivalent O(3)Fe4 tetrahedra,  a cornercorner with one O(4)Fe4 trigonal pyramid,  a cornercorner with one O(1)MgFe3 trigonal pyramid,  a cornercorner with one O(2)MgFe3 trigonal pyramid,  an edgeedge with one O(4)Fe4 trigonal pyramid,  an edgeedge with one O(1)MgFe3 trigonal pyramid, and  an edgeedge with one O(2)MgFe3 trigonal pyramid. In the third F site, F(3) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(2), one Fe(3), and one Fe(4) atom. In the fourth F site, F(4) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(1), one Fe(2), and one Fe(4) atom. is represented by the CIF file [CIF]
data_MgFe4(OF)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.859
_cell_length_b   5.410
_cell_length_c   5.422
_cell_angle_alpha   105.736
_cell_angle_beta   69.815
_cell_angle_gamma   73.644
_symmetry_Int_Tables_number   1
_cell_volume   141.243
_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  0.747  0.433  0.693  1.0
  Fe  Fe1  1  0.258  0.941  0.124  1.0
  Fe  Fe2  1  0.776  0.717  0.308  1.0
  Fe  Fe3  1  0.242  0.387  0.681  1.0
  Fe  Fe4  1  0.733  0.080  0.980  1.0
  O  O5  1  0.599  0.847  0.785  1.0
  O  O6  1  0.909  0.363  0.955  1.0
  O  O7  1  0.023  0.803  0.976  1.0
  O  O8  1  0.483  0.007  0.328  1.0
  F  F9  1  0.446  0.395  0.952  1.0
  F  F10  1  0.058  0.420  0.391  1.0
  F  F11  1  0.558  0.463  0.449  1.0
  F  F12  1  0.936  0.001  0.490  1.0
[/CIF]
.
The material described by MgFe4(OF)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(2), one F(1), one F(2), one F(3), and one F(4) atom to form MgO2F4 octahedra that share corners with two equivalent Fe(2)O4F3 pentagonal bipyramids, corners with two equivalent Fe(4)O4F3 pentagonal bipyramids, edges with two equivalent Fe(3)O3F3 octahedra,  a faceface with one Fe(2)O4F3 pentagonal bipyramid, and  a faceface with one Fe(4)O4F3 pentagonal bipyramid. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(4), one F(1), one F(2), and one F(4) atom. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), one O(4), one F(2), one F(3), and one F(4) atom to form distorted FeO4F3 pentagonal bipyramids that share corners with two equivalent Mg(1)O2F4 octahedra, corners with three equivalent Fe(3)O3F3 octahedra,  an edgeedge with one Fe(3)O3F3 octahedra, edges with three equivalent Fe(4)O4F3 pentagonal bipyramids, and  a faceface with one Mg(1)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 22-68°. In the third Fe site, Fe(3) is bonded to one O(2), one O(3), one O(4), one F(1), one F(2), and one F(3) atom to form FeO3F3 octahedra that share corners with three equivalent Fe(2)O4F3 pentagonal bipyramids, corners with three equivalent Fe(4)O4F3 pentagonal bipyramids, edges with two equivalent Mg(1)O2F4 octahedra,  an edgeedge with one Fe(2)O4F3 pentagonal bipyramid, and  an edgeedge with one Fe(4)O4F3 pentagonal bipyramid. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(2), one O(3), one O(4), one F(1), one F(3), and one F(4) atom to form distorted FeO4F3 pentagonal bipyramids that share corners with two equivalent Mg(1)O2F4 octahedra, corners with three equivalent Fe(3)O3F3 octahedra,  an edgeedge with one Fe(3)O3F3 octahedra, edges with three equivalent Fe(2)O4F3 pentagonal bipyramids, and  a faceface with one Mg(1)O2F4 octahedra. The corner-sharing octahedral tilt angles range from 40-61°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Fe(1), one Fe(2), and one Fe(4) atom to form distorted OMgFe3 trigonal pyramids that share corners with three equivalent O(3)Fe4 tetrahedra,  a cornercorner with one O(4)Fe4 trigonal pyramid,  a cornercorner with one F(2)MgFe3 trigonal pyramid, corners with three equivalent O(2)MgFe3 trigonal pyramids,  an edgeedge with one O(4)Fe4 trigonal pyramid, and  an edgeedge with one F(2)MgFe3 trigonal pyramid. In the second O site, O(2) is bonded to one Mg(1), one Fe(2), one Fe(3), and one Fe(4) atom to form distorted OMgFe3 trigonal pyramids that share  a cornercorner with one O(3)Fe4 tetrahedra,  a cornercorner with one F(2)MgFe3 trigonal pyramid, corners with three equivalent O(4)Fe4 trigonal pyramids, corners with three equivalent O(1)MgFe3 trigonal pyramids,  an edgeedge with one O(3)Fe4 tetrahedra, and  an edgeedge with one F(2)MgFe3 trigonal pyramid. In the third O site, O(3) is bonded to one Fe(1), one Fe(2), one Fe(3), and one Fe(4) atom to form OFe4 tetrahedra that share  a cornercorner with one O(2)MgFe3 trigonal pyramid, corners with two equivalent O(4)Fe4 trigonal pyramids, corners with three equivalent O(1)MgFe3 trigonal pyramids, corners with three equivalent F(2)MgFe3 trigonal pyramids,  an edgeedge with one O(4)Fe4 trigonal pyramid, and  an edgeedge with one O(2)MgFe3 trigonal pyramid. In the fourth O site, O(4) is bonded to one Fe(1), one Fe(2), one Fe(3), and one Fe(4) atom to form distorted OFe4 trigonal pyramids that share corners with two equivalent O(3)Fe4 tetrahedra,  a cornercorner with one O(1)MgFe3 trigonal pyramid,  a cornercorner with one F(2)MgFe3 trigonal pyramid, corners with three equivalent O(2)MgFe3 trigonal pyramids,  an edgeedge with one O(3)Fe4 tetrahedra,  an edgeedge with one O(1)MgFe3 trigonal pyramid, and  an edgeedge with one F(2)MgFe3 trigonal pyramid. There are four inequivalent F sites. In the first F site, F(1) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(1), one Fe(3), and one Fe(4) atom. In the second F site, F(2) is bonded to one Mg(1), one Fe(1), one Fe(2), and one Fe(3) atom to form distorted FMgFe3 trigonal pyramids that share corners with three equivalent O(3)Fe4 tetrahedra,  a cornercorner with one O(4)Fe4 trigonal pyramid,  a cornercorner with one O(1)MgFe3 trigonal pyramid,  a cornercorner with one O(2)MgFe3 trigonal pyramid,  an edgeedge with one O(4)Fe4 trigonal pyramid,  an edgeedge with one O(1)MgFe3 trigonal pyramid, and  an edgeedge with one O(2)MgFe3 trigonal pyramid. In the third F site, F(3) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(2), one Fe(3), and one Fe(4) atom. In the fourth F site, F(4) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(1), one Fe(2), and one Fe(4) atom. is represented by the CIF file [CIF]
data_MgFe4(OF)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.859
_cell_length_b   5.410
_cell_length_c   5.422
_cell_angle_alpha   105.736
_cell_angle_beta   69.815
_cell_angle_gamma   73.644
_symmetry_Int_Tables_number   1
_cell_volume   141.243
_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  0.747  0.433  0.693  1.0
  Fe  Fe1  1  0.258  0.941  0.124  1.0
  Fe  Fe2  1  0.776  0.717  0.308  1.0
  Fe  Fe3  1  0.242  0.387  0.681  1.0
  Fe  Fe4  1  0.733  0.080  0.980  1.0
  O  O5  1  0.599  0.847  0.785  1.0
  O  O6  1  0.909  0.363  0.955  1.0
  O  O7  1  0.023  0.803  0.976  1.0
  O  O8  1  0.483  0.007  0.328  1.0
  F  F9  1  0.446  0.395  0.952  1.0
  F  F10  1  0.058  0.420  0.391  1.0
  F  F11  1  0.558  0.463  0.449  1.0
  F  F12  1  0.936  0.001  0.490  1.0
[/CIF]
.