The material described by MgFe4(OF)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(2), one O(3), one O(4), one F(1), one F(2), and one F(4) atom to form distorted MgO3F3 octahedra that share  a cornercorner with one Fe(1)O3F2 trigonal bipyramid,  a cornercorner with one Fe(2)O3F2 trigonal bipyramid, corners with four equivalent Fe(3)O3F2 trigonal bipyramids,  an edgeedge with one Fe(1)O3F2 trigonal bipyramid,  an edgeedge with one Fe(2)O3F2 trigonal bipyramid,  an edgeedge with one Fe(4)O3F2 trigonal bipyramid, and  a faceface with one Fe(4)O3F2 trigonal bipyramid. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(4), one F(3), and one F(4) atom to form distorted FeO3F2 trigonal bipyramids that share  a cornercorner with one Mg(1)O3F3 octahedra, corners with two equivalent Fe(3)O3F2 trigonal bipyramids, corners with two equivalent Fe(4)O3F2 trigonal bipyramids,  an edgeedge with one Mg(1)O3F3 octahedra, and edges with two equivalent Fe(2)O3F2 trigonal bipyramids. The corner-sharing octahedral tilt angles are 62°. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), one F(3), and one F(4) atom to form FeO3F2 trigonal bipyramids that share  a cornercorner with one Mg(1)O3F3 octahedra, corners with two equivalent Fe(3)O3F2 trigonal bipyramids, corners with two equivalent Fe(4)O3F2 trigonal bipyramids,  an edgeedge with one Mg(1)O3F3 octahedra, and edges with two equivalent Fe(1)O3F2 trigonal bipyramids. The corner-sharing octahedral tilt angles are 62°. In the third Fe site, Fe(3) is bonded to one O(1), one O(3), one O(4), one F(1), and one F(2) atom to form distorted FeO3F2 trigonal bipyramids that share corners with four equivalent Mg(1)O3F3 octahedra, corners with two equivalent Fe(1)O3F2 trigonal bipyramids, corners with two equivalent Fe(2)O3F2 trigonal bipyramids, and edges with two equivalent Fe(4)O3F2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 24-53°. In the fourth Fe site, Fe(4) is bonded to one O(2), one O(3), one O(4), one F(1), and one F(2) atom to form distorted FeO3F2 trigonal bipyramids that share corners with two equivalent Fe(1)O3F2 trigonal bipyramids, corners with two equivalent Fe(2)O3F2 trigonal bipyramids,  an edgeedge with one Mg(1)O3F3 octahedra, edges with two equivalent Fe(3)O3F2 trigonal bipyramids, and  a faceface with one Mg(1)O3F3 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(3) atom. In the second O site, O(2) is bonded in a trigonal pyramidal geometry to one Mg(1), one Fe(1), one Fe(2), and one Fe(4) atom. In the third O site, O(3) is bonded in a see-saw-like geometry to one Mg(1), one Fe(2), one Fe(3), and one Fe(4) atom. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(3), and one Fe(4) atom. There are four inequivalent F sites. In the first F site, F(1) is bonded in a T-shaped geometry to one Mg(1), one Fe(3), and one Fe(4) atom. In the second F site, F(2) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(3), and one Fe(4) atom. In the third F site, F(3) is bonded in an L-shaped geometry to one Fe(1) and one Fe(2) atom. In the fourth F site, F(4) is bonded in a 3-coordinate geometry to one Mg(1), one Fe(1), and one Fe(2) atom. is represented by the CIF file [CIF]
data_MgFe4(OF)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.497
_cell_length_b   5.352
_cell_length_c   5.827
_cell_angle_alpha   86.750
_cell_angle_beta   86.870
_cell_angle_gamma   93.442
_symmetry_Int_Tables_number   1
_cell_volume   170.529
_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  0.515  0.039  0.745  1.0
  Fe  Fe1  1  0.957  0.875  0.007  1.0
  Fe  Fe2  1  0.097  0.033  0.464  1.0
  Fe  Fe3  1  0.437  0.558  0.251  1.0
  Fe  Fe4  1  0.397  0.550  0.750  1.0
  O  O5  1  0.145  0.732  0.246  1.0
  O  O6  1  0.187  0.832  0.757  1.0
  O  O7  1  0.384  0.297  0.501  1.0
  O  O8  1  0.631  0.727  0.985  1.0
  F  F9  1  0.401  0.264  0.004  1.0
  F  F10  1  0.611  0.776  0.484  1.0
  F  F11  1  0.909  0.162  0.192  1.0
  F  F12  1  0.854  0.155  0.738  1.0
[/CIF]
.
The material described by MgFe4(OF)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(2), one O(3), one O(4), one F(1), one F(2), and one F(4) atom to form distorted MgO3F3 octahedra that share  a cornercorner with one Fe(1)O3F2 trigonal bipyramid,  a cornercorner with one Fe(2)O3F2 trigonal bipyramid, corners with four equivalent Fe(3)O3F2 trigonal bipyramids,  an edgeedge with one Fe(1)O3F2 trigonal bipyramid,  an edgeedge with one Fe(2)O3F2 trigonal bipyramid,  an edgeedge with one Fe(4)O3F2 trigonal bipyramid, and  a faceface with one Fe(4)O3F2 trigonal bipyramid. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(4), one F(3), and one F(4) atom to form distorted FeO3F2 trigonal bipyramids that share  a cornercorner with one Mg(1)O3F3 octahedra, corners with two equivalent Fe(3)O3F2 trigonal bipyramids, corners with two equivalent Fe(4)O3F2 trigonal bipyramids,  an edgeedge with one Mg(1)O3F3 octahedra, and edges with two equivalent Fe(2)O3F2 trigonal bipyramids. The corner-sharing octahedral tilt angles are 62°. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), one F(3), and one F(4) atom to form FeO3F2 trigonal bipyramids that share  a cornercorner with one Mg(1)O3F3 octahedra, corners with two equivalent Fe(3)O3F2 trigonal bipyramids, corners with two equivalent Fe(4)O3F2 trigonal bipyramids,  an edgeedge with one Mg(1)O3F3 octahedra, and edges with two equivalent Fe(1)O3F2 trigonal bipyramids. The corner-sharing octahedral tilt angles are 62°. In the third Fe site, Fe(3) is bonded to one O(1), one O(3), one O(4), one F(1), and one F(2) atom to form distorted FeO3F2 trigonal bipyramids that share corners with four equivalent Mg(1)O3F3 octahedra, corners with two equivalent Fe(1)O3F2 trigonal bipyramids, corners with two equivalent Fe(2)O3F2 trigonal bipyramids, and edges with two equivalent Fe(4)O3F2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 24-53°. In the fourth Fe site, Fe(4) is bonded to one O(2), one O(3), one O(4), one F(1), and one F(2) atom to form distorted FeO3F2 trigonal bipyramids that share corners with two equivalent Fe(1)O3F2 trigonal bipyramids, corners with two equivalent Fe(2)O3F2 trigonal bipyramids,  an edgeedge with one Mg(1)O3F3 octahedra, edges with two equivalent Fe(3)O3F2 trigonal bipyramids, and  a faceface with one Mg(1)O3F3 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(2), and one Fe(3) atom. In the second O site, O(2) is bonded in a trigonal pyramidal geometry to one Mg(1), one Fe(1), one Fe(2), and one Fe(4) atom. In the third O site, O(3) is bonded in a see-saw-like geometry to one Mg(1), one Fe(2), one Fe(3), and one Fe(4) atom. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(3), and one Fe(4) atom. There are four inequivalent F sites. In the first F site, F(1) is bonded in a T-shaped geometry to one Mg(1), one Fe(3), and one Fe(4) atom. In the second F site, F(2) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(3), and one Fe(4) atom. In the third F site, F(3) is bonded in an L-shaped geometry to one Fe(1) and one Fe(2) atom. In the fourth F site, F(4) is bonded in a 3-coordinate geometry to one Mg(1), one Fe(1), and one Fe(2) atom. is represented by the CIF file [CIF]
data_MgFe4(OF)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.497
_cell_length_b   5.352
_cell_length_c   5.827
_cell_angle_alpha   86.750
_cell_angle_beta   86.870
_cell_angle_gamma   93.442
_symmetry_Int_Tables_number   1
_cell_volume   170.529
_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  0.515  0.039  0.745  1.0
  Fe  Fe1  1  0.957  0.875  0.007  1.0
  Fe  Fe2  1  0.097  0.033  0.464  1.0
  Fe  Fe3  1  0.437  0.558  0.251  1.0
  Fe  Fe4  1  0.397  0.550  0.750  1.0
  O  O5  1  0.145  0.732  0.246  1.0
  O  O6  1  0.187  0.832  0.757  1.0
  O  O7  1  0.384  0.297  0.501  1.0
  O  O8  1  0.631  0.727  0.985  1.0
  F  F9  1  0.401  0.264  0.004  1.0
  F  F10  1  0.611  0.776  0.484  1.0
  F  F11  1  0.909  0.162  0.192  1.0
  F  F12  1  0.854  0.155  0.738  1.0
[/CIF]
.