The crystal structure described by MgFe4(OF)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(3), one O(4), one F(3), and one F(4) atom to form distorted MgO3F2 trigonal bipyramids that share  a cornercorner with one Fe(2)O3F2 trigonal bipyramid, corners with three equivalent Fe(3)O3F2 trigonal bipyramids,  an edgeedge with one Fe(2)O3F2 trigonal bipyramid, and edges with two equivalent Fe(1)O3F2 trigonal bipyramids. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), one O(4), one F(1), and one F(3) atom to form distorted FeO3F2 trigonal bipyramids that share corners with two equivalent Fe(2)O3F2 trigonal bipyramids, edges with two equivalent Mg(1)O3F2 trigonal bipyramids, and edges with two equivalent Fe(3)O3F2 trigonal bipyramids. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(4), one F(2), and one F(4) atom to form FeO3F2 trigonal bipyramids that share  a cornercorner with one Mg(1)O3F2 trigonal bipyramid, corners with two equivalent Fe(1)O3F2 trigonal bipyramids, corners with two equivalent Fe(3)O3F2 trigonal bipyramids, and  an edgeedge with one Mg(1)O3F2 trigonal bipyramid. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), one O(3), one F(1), and one F(3) atom to form FeO3F2 trigonal bipyramids that share corners with two equivalent Fe(2)O3F2 trigonal bipyramids, corners with three equivalent Mg(1)O3F2 trigonal bipyramids, and edges with two equivalent Fe(1)O3F2 trigonal bipyramids. In the fourth Fe site, Fe(4) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), one F(2), and one F(4) atom. 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(3) atom to form a mixture of distorted edge and corner-sharing OMgFe3 trigonal pyramids. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(3), and one Fe(4) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(3), and one Fe(4) atom. In the fourth O site, O(4) is bonded to one Mg(1), one Fe(1), one Fe(2), and one Fe(4) atom to form a mixture of edge and corner-sharing OMgFe3 trigonal pyramids. There are four inequivalent F sites. In the first F site, F(1) is bonded in a water-like geometry to one Fe(1) and one Fe(3) atom. In the second F site, F(2) is bonded in a water-like geometry to one Fe(2) and one Fe(4) atom. In the third F site, F(3) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(1), and one Fe(3) atom. In the fourth F site, F(4) is bonded in a distorted T-shaped geometry to one Mg(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   5.738
_cell_length_b   5.505
_cell_length_c   5.444
_cell_angle_alpha   91.397
_cell_angle_beta   100.061
_cell_angle_gamma   86.031
_symmetry_Int_Tables_number   1
_cell_volume   168.902
_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  0.931  0.027  0.533  1.0
  Fe  Fe1  1  0.028  0.104  0.074  1.0
  Fe  Fe2  1  0.257  0.429  0.589  1.0
  Fe  Fe3  1  0.504  0.909  0.933  1.0
  Fe  Fe4  1  0.700  0.576  0.402  1.0
  O  O5  1  0.234  0.147  0.792  1.0
  O  O6  1  0.503  0.649  0.693  1.0
  O  O7  1  0.768  0.878  0.208  1.0
  O  O8  1  0.977  0.330  0.353  1.0
  F  F9  1  0.285  0.816  0.156  1.0
  F  F10  1  0.447  0.316  0.331  1.0
  F  F11  1  0.728  0.121  0.777  1.0
  F  F12  1  0.014  0.698  0.673  1.0
[/CIF]
.
The crystal structure described by MgFe4(OF)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(3), one O(4), one F(3), and one F(4) atom to form distorted MgO3F2 trigonal bipyramids that share  a cornercorner with one Fe(2)O3F2 trigonal bipyramid, corners with three equivalent Fe(3)O3F2 trigonal bipyramids,  an edgeedge with one Fe(2)O3F2 trigonal bipyramid, and edges with two equivalent Fe(1)O3F2 trigonal bipyramids. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), one O(4), one F(1), and one F(3) atom to form distorted FeO3F2 trigonal bipyramids that share corners with two equivalent Fe(2)O3F2 trigonal bipyramids, edges with two equivalent Mg(1)O3F2 trigonal bipyramids, and edges with two equivalent Fe(3)O3F2 trigonal bipyramids. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(4), one F(2), and one F(4) atom to form FeO3F2 trigonal bipyramids that share  a cornercorner with one Mg(1)O3F2 trigonal bipyramid, corners with two equivalent Fe(1)O3F2 trigonal bipyramids, corners with two equivalent Fe(3)O3F2 trigonal bipyramids, and  an edgeedge with one Mg(1)O3F2 trigonal bipyramid. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), one O(3), one F(1), and one F(3) atom to form FeO3F2 trigonal bipyramids that share corners with two equivalent Fe(2)O3F2 trigonal bipyramids, corners with three equivalent Mg(1)O3F2 trigonal bipyramids, and edges with two equivalent Fe(1)O3F2 trigonal bipyramids. In the fourth Fe site, Fe(4) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), one F(2), and one F(4) atom. 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(3) atom to form a mixture of distorted edge and corner-sharing OMgFe3 trigonal pyramids. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(3), and one Fe(4) atom. In the third O site, O(3) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(3), and one Fe(4) atom. In the fourth O site, O(4) is bonded to one Mg(1), one Fe(1), one Fe(2), and one Fe(4) atom to form a mixture of edge and corner-sharing OMgFe3 trigonal pyramids. There are four inequivalent F sites. In the first F site, F(1) is bonded in a water-like geometry to one Fe(1) and one Fe(3) atom. In the second F site, F(2) is bonded in a water-like geometry to one Fe(2) and one Fe(4) atom. In the third F site, F(3) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(1), and one Fe(3) atom. In the fourth F site, F(4) is bonded in a distorted T-shaped geometry to one Mg(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   5.738
_cell_length_b   5.505
_cell_length_c   5.444
_cell_angle_alpha   91.397
_cell_angle_beta   100.061
_cell_angle_gamma   86.031
_symmetry_Int_Tables_number   1
_cell_volume   168.902
_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  0.931  0.027  0.533  1.0
  Fe  Fe1  1  0.028  0.104  0.074  1.0
  Fe  Fe2  1  0.257  0.429  0.589  1.0
  Fe  Fe3  1  0.504  0.909  0.933  1.0
  Fe  Fe4  1  0.700  0.576  0.402  1.0
  O  O5  1  0.234  0.147  0.792  1.0
  O  O6  1  0.503  0.649  0.693  1.0
  O  O7  1  0.768  0.878  0.208  1.0
  O  O8  1  0.977  0.330  0.353  1.0
  F  F9  1  0.285  0.816  0.156  1.0
  F  F10  1  0.447  0.316  0.331  1.0
  F  F11  1  0.728  0.121  0.777  1.0
  F  F12  1  0.014  0.698  0.673  1.0
[/CIF]
.