The compound described by MgFe8(OF)8 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one F(5), one F(8), two equivalent F(6), and two equivalent F(7) atoms to form MgF6 octahedra that share corners with two equivalent Fe(8)O3F tetrahedra, edges with two equivalent Mg(1)F6 octahedra, and edges with two equivalent Fe(6)F6 octahedra. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(2), and two equivalent F(8) atoms. In the second Fe site, Fe(2) is bonded to one O(4), one O(7), two equivalent O(1), and two equivalent O(8) atoms to form FeO6 octahedra that share corners with two equivalent Fe(3)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, corners with two equivalent Fe(8)O3F tetrahedra, and edges with two equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-56°. In the third Fe site, Fe(3) is bonded to one O(1), two equivalent O(3), one F(3), and two equivalent F(1) atoms to form distorted FeO3F3 octahedra that share corners with two equivalent Fe(6)F6 octahedra, corners with two equivalent Fe(5)O3F3 octahedra, corners with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Fe(3)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-52°. In the fourth Fe site, Fe(4) is bonded to one O(2), two equivalent O(4), one F(4), and two equivalent F(2) atoms to form distorted FeO3F3 octahedra that share corners with two equivalent Fe(6)F6 octahedra, corners with two equivalent Fe(5)O3F3 octahedra, corners with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Fe(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 43-56°. In the fifth Fe site, Fe(5) is bonded to one O(6), two equivalent O(5), one F(1), and two equivalent F(4) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(3)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, corners with two equivalent Fe(8)O3F tetrahedra, and edges with two equivalent Fe(5)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-48°. In the sixth Fe site, Fe(6) is bonded to one F(2), one F(6), two equivalent F(3), and two equivalent F(5) atoms to form distorted FeF6 octahedra that share corners with two equivalent Fe(3)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, edges with two equivalent Mg(1)F6 octahedra, and edges with two equivalent Fe(6)F6 octahedra. The corner-sharing octahedral tilt angles range from 43-52°. In the seventh Fe site, Fe(7) is bonded in a trigonal planar geometry to one O(5) and two equivalent O(7) atoms. In the eighth Fe site, Fe(8) is bonded to one O(8), two equivalent O(6), and one F(7) atom to form distorted FeO3F tetrahedra that share corners with two equivalent Mg(1)F6 octahedra, corners with two equivalent Fe(5)O3F3 octahedra, corners with two equivalent Fe(2)O6 octahedra, and corners with two equivalent Fe(8)O3F tetrahedra. The corner-sharing octahedral tilt angles range from 38-79°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(3) and two equivalent Fe(2) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(4) and two equivalent Fe(1) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(1) and two equivalent Fe(3) atoms. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Fe(4) atoms. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to one Fe(7) and two equivalent Fe(5) atoms. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Fe(5) and two equivalent Fe(8) atoms. In the seventh O site, O(7) is bonded in a trigonal non-coplanar geometry to one Fe(2) and two equivalent Fe(7) atoms. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Fe(8) and two equivalent Fe(2) atoms. There are eight inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to one Fe(5) and two equivalent Fe(3) atoms. In the second F site, F(2) is bonded in a distorted T-shaped geometry to one Fe(6) and two equivalent Fe(4) atoms. In the third F site, F(3) is bonded in a distorted trigonal planar geometry to one Fe(3) and two equivalent Fe(6) atoms. In the fourth F site, F(4) is bonded in a distorted T-shaped geometry to one Fe(4) and two equivalent Fe(5) atoms. In the fifth F site, F(5) is bonded in a trigonal non-coplanar geometry to one Mg(1) and two equivalent Fe(6) atoms. In the sixth F site, F(6) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Mg(1) and one Fe(6) atom. In the seventh F site, F(7) is bonded in a T-shaped geometry to two equivalent Mg(1) and one Fe(8) atom. In the eighth F site, F(8) is bonded in a 3-coordinate geometry to one Mg(1) and two equivalent Fe(1) atoms. is represented by the CIF card [CIF]
data_MgFe8(OF)8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.070
_cell_length_b   9.843
_cell_length_c   3.126
_cell_angle_alpha   91.805
_cell_angle_beta   90.496
_cell_angle_gamma   89.224
_symmetry_Int_Tables_number   1
_cell_volume   309.701
_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  0.744  0.001  0.437  1.0
  Fe  Fe1  1  0.070  0.005  0.001  1.0
  Fe  Fe2  1  0.012  0.501  0.999  1.0
  Fe  Fe3  1  0.228  0.270  0.499  1.0
  Fe  Fe4  1  0.225  0.729  0.510  1.0
  Fe  Fe5  1  0.505  0.493  0.024  1.0
  Fe  Fe6  1  0.462  0.997  0.957  1.0
  Fe  Fe7  1  0.767  0.348  0.480  1.0
  Fe  Fe8  1  0.745  0.676  0.575  1.0
  O  O9  1  0.109  0.414  0.495  1.0
  O  O10  1  0.123  0.905  0.497  1.0
  O  O11  1  0.167  0.164  0.989  1.0
  O  O12  1  0.150  0.651  0.002  1.0
  O  O13  1  0.578  0.402  0.518  1.0
  O  O14  1  0.642  0.635  0.062  1.0
  O  O15  1  0.872  0.363  0.984  1.0
  O  O16  1  0.911  0.606  0.507  1.0
  F  F17  1  0.346  0.357  0.004  1.0
  F  F18  1  0.343  0.832  0.997  1.0
  F  F19  1  0.395  0.116  0.483  1.0
  F  F20  1  0.395  0.597  0.514  1.0
  F  F21  1  0.572  0.904  0.441  1.0
  F  F22  1  0.669  0.102  0.952  1.0
  F  F23  1  0.797  0.865  0.889  1.0
  F  F24  1  0.924  0.067  0.434  1.0
[/CIF]
.
The compound described by MgFe8(OF)8 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one F(5), one F(8), two equivalent F(6), and two equivalent F(7) atoms to form MgF6 octahedra that share corners with two equivalent Fe(8)O3F tetrahedra, edges with two equivalent Mg(1)F6 octahedra, and edges with two equivalent Fe(6)F6 octahedra. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(2), and two equivalent F(8) atoms. In the second Fe site, Fe(2) is bonded to one O(4), one O(7), two equivalent O(1), and two equivalent O(8) atoms to form FeO6 octahedra that share corners with two equivalent Fe(3)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, corners with two equivalent Fe(8)O3F tetrahedra, and edges with two equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-56°. In the third Fe site, Fe(3) is bonded to one O(1), two equivalent O(3), one F(3), and two equivalent F(1) atoms to form distorted FeO3F3 octahedra that share corners with two equivalent Fe(6)F6 octahedra, corners with two equivalent Fe(5)O3F3 octahedra, corners with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Fe(3)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-52°. In the fourth Fe site, Fe(4) is bonded to one O(2), two equivalent O(4), one F(4), and two equivalent F(2) atoms to form distorted FeO3F3 octahedra that share corners with two equivalent Fe(6)F6 octahedra, corners with two equivalent Fe(5)O3F3 octahedra, corners with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Fe(4)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 43-56°. In the fifth Fe site, Fe(5) is bonded to one O(6), two equivalent O(5), one F(1), and two equivalent F(4) atoms to form FeO3F3 octahedra that share corners with two equivalent Fe(3)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, corners with two equivalent Fe(8)O3F tetrahedra, and edges with two equivalent Fe(5)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 46-48°. In the sixth Fe site, Fe(6) is bonded to one F(2), one F(6), two equivalent F(3), and two equivalent F(5) atoms to form distorted FeF6 octahedra that share corners with two equivalent Fe(3)O3F3 octahedra, corners with two equivalent Fe(4)O3F3 octahedra, edges with two equivalent Mg(1)F6 octahedra, and edges with two equivalent Fe(6)F6 octahedra. The corner-sharing octahedral tilt angles range from 43-52°. In the seventh Fe site, Fe(7) is bonded in a trigonal planar geometry to one O(5) and two equivalent O(7) atoms. In the eighth Fe site, Fe(8) is bonded to one O(8), two equivalent O(6), and one F(7) atom to form distorted FeO3F tetrahedra that share corners with two equivalent Mg(1)F6 octahedra, corners with two equivalent Fe(5)O3F3 octahedra, corners with two equivalent Fe(2)O6 octahedra, and corners with two equivalent Fe(8)O3F tetrahedra. The corner-sharing octahedral tilt angles range from 38-79°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Fe(3) and two equivalent Fe(2) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(4) and two equivalent Fe(1) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(1) and two equivalent Fe(3) atoms. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Fe(4) atoms. In the fifth O site, O(5) is bonded in a trigonal non-coplanar geometry to one Fe(7) and two equivalent Fe(5) atoms. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Fe(5) and two equivalent Fe(8) atoms. In the seventh O site, O(7) is bonded in a trigonal non-coplanar geometry to one Fe(2) and two equivalent Fe(7) atoms. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Fe(8) and two equivalent Fe(2) atoms. There are eight inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to one Fe(5) and two equivalent Fe(3) atoms. In the second F site, F(2) is bonded in a distorted T-shaped geometry to one Fe(6) and two equivalent Fe(4) atoms. In the third F site, F(3) is bonded in a distorted trigonal planar geometry to one Fe(3) and two equivalent Fe(6) atoms. In the fourth F site, F(4) is bonded in a distorted T-shaped geometry to one Fe(4) and two equivalent Fe(5) atoms. In the fifth F site, F(5) is bonded in a trigonal non-coplanar geometry to one Mg(1) and two equivalent Fe(6) atoms. In the sixth F site, F(6) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Mg(1) and one Fe(6) atom. In the seventh F site, F(7) is bonded in a T-shaped geometry to two equivalent Mg(1) and one Fe(8) atom. In the eighth F site, F(8) is bonded in a 3-coordinate geometry to one Mg(1) and two equivalent Fe(1) atoms. is represented by the CIF card [CIF]
data_MgFe8(OF)8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.070
_cell_length_b   9.843
_cell_length_c   3.126
_cell_angle_alpha   91.805
_cell_angle_beta   90.496
_cell_angle_gamma   89.224
_symmetry_Int_Tables_number   1
_cell_volume   309.701
_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  0.744  0.001  0.437  1.0
  Fe  Fe1  1  0.070  0.005  0.001  1.0
  Fe  Fe2  1  0.012  0.501  0.999  1.0
  Fe  Fe3  1  0.228  0.270  0.499  1.0
  Fe  Fe4  1  0.225  0.729  0.510  1.0
  Fe  Fe5  1  0.505  0.493  0.024  1.0
  Fe  Fe6  1  0.462  0.997  0.957  1.0
  Fe  Fe7  1  0.767  0.348  0.480  1.0
  Fe  Fe8  1  0.745  0.676  0.575  1.0
  O  O9  1  0.109  0.414  0.495  1.0
  O  O10  1  0.123  0.905  0.497  1.0
  O  O11  1  0.167  0.164  0.989  1.0
  O  O12  1  0.150  0.651  0.002  1.0
  O  O13  1  0.578  0.402  0.518  1.0
  O  O14  1  0.642  0.635  0.062  1.0
  O  O15  1  0.872  0.363  0.984  1.0
  O  O16  1  0.911  0.606  0.507  1.0
  F  F17  1  0.346  0.357  0.004  1.0
  F  F18  1  0.343  0.832  0.997  1.0
  F  F19  1  0.395  0.116  0.483  1.0
  F  F20  1  0.395  0.597  0.514  1.0
  F  F21  1  0.572  0.904  0.441  1.0
  F  F22  1  0.669  0.102  0.952  1.0
  F  F23  1  0.797  0.865  0.889  1.0
  F  F24  1  0.924  0.067  0.434  1.0
[/CIF]
.