The crystal structure described by MgFe8(O7F)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a distorted rectangular see-saw-like geometry to one O(10), one O(12), one O(13), and one O(6) atom. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(12), one O(3), one O(5), one O(9), and one F(2) atom to form FeO5F octahedra that share corners with three equivalent Fe(7)O5 trigonal bipyramids,  an edgeedge with one Fe(4)O5F octahedra, and  an edgeedge with one Fe(2)O6 octahedra. In the second Fe site, Fe(2) is bonded to one O(1), one O(10), one O(12), one O(13), one O(4), and one O(6) atom to form edge-sharing FeO6 octahedra. In the third Fe site, Fe(3) is bonded to one O(13), one O(14), one O(2), one O(4), one O(7), and one F(1) atom to form FeO5F octahedra that share  an edgeedge with one Fe(4)O5F octahedra and  an edgeedge with one Fe(2)O6 octahedra. In the fourth Fe site, Fe(4) is bonded to one O(11), one O(14), one O(2), one O(3), one O(8), and one F(2) atom to form FeO5F octahedra that share corners with three equivalent Fe(7)O5 trigonal bipyramids,  an edgeedge with one Fe(1)O5F octahedra, and  an edgeedge with one Fe(3)O5F octahedra. In the fifth Fe site, Fe(5) is bonded in a 5-coordinate geometry to one O(1), one O(10), one O(5), one O(6), and one O(9) atom. In the sixth Fe site, Fe(6) is bonded in a 5-coordinate geometry to one O(11), one O(14), one O(7), one O(8), and one F(1) atom. In the seventh Fe site, Fe(7) is bonded to one O(11), one O(3), one O(5), one O(8), and one O(9) atom to form distorted corner-sharing FeO5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 46-51°. In the eighth Fe site, Fe(8) is bonded in a 5-coordinate geometry to one O(10), one O(4), one O(6), one O(7), and one F(1) atom. There are fourteen 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(5) atom. In the second O site, O(2) is bonded in a water-like geometry to one Fe(3) and one Fe(4) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(4), and one Fe(7) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(3), and one Fe(8) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(5), and one Fe(7) atom. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(2), one Fe(5), and one Fe(8) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Fe(3), one Fe(6), and one Fe(8) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Fe(4), one Fe(6), and one Fe(7) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(5), and one Fe(7) atom. In the tenth O site, O(10) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(2), one Fe(5), and one Fe(8) atom. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one Fe(4), one Fe(6), and one Fe(7) atom. In the twelfth O site, O(12) is bonded in a T-shaped geometry to one Mg(1), one Fe(1), and one Fe(2) atom. In the thirteenth O site, O(13) is bonded in a T-shaped geometry to one Mg(1), one Fe(2), and one Fe(3) atom. In the fourteenth O site, O(14) is bonded in a distorted T-shaped geometry to one Fe(3), one Fe(4), and one Fe(6) atom. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(6), and one Fe(8) atom. In the second F site, F(2) is bonded in an L-shaped geometry to one Fe(1) and one Fe(4) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgFe8(O7F)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.173
_cell_length_b   5.175
_cell_length_c   11.605
_cell_angle_alpha   90.645
_cell_angle_beta   89.401
_cell_angle_gamma   102.090
_symmetry_Int_Tables_number   1
_cell_volume   303.739
_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  0.699  0.294  0.256  1.0
  Fe  Fe1  1  0.006  0.990  0.998  1.0
  Fe  Fe2  1  0.031  0.964  0.251  1.0
  Fe  Fe3  1  0.029  0.022  0.503  1.0
  Fe  Fe4  1  0.003  0.984  0.749  1.0
  Fe  Fe5  1  0.419  0.579  0.119  1.0
  Fe  Fe6  1  0.581  0.394  0.633  1.0
  Fe  Fe7  1  0.426  0.570  0.868  1.0
  Fe  Fe8  1  0.409  0.576  0.385  1.0
  O  O9  1  0.181  0.813  0.128  1.0
  O  O10  1  0.166  0.856  0.614  1.0
  O  O11  1  0.173  0.820  0.873  1.0
  O  O12  1  0.185  0.817  0.375  1.0
  O  O13  1  0.275  0.341  0.993  1.0
  O  O14  1  0.322  0.311  0.250  1.0
  O  O15  1  0.342  0.310  0.501  1.0
  O  O16  1  0.310  0.305  0.753  1.0
  O  O17  1  0.656  0.719  0.993  1.0
  O  O18  1  0.685  0.673  0.254  1.0
  O  O19  1  0.687  0.678  0.749  1.0
  O  O20  1  0.865  0.125  0.139  1.0
  O  O21  1  0.873  0.138  0.373  1.0
  O  O22  1  0.833  0.170  0.622  1.0
  F  F23  1  0.707  0.686  0.500  1.0
  F  F24  1  0.832  0.158  0.872  1.0
[/CIF]
.
The crystal structure described by MgFe8(O7F)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a distorted rectangular see-saw-like geometry to one O(10), one O(12), one O(13), and one O(6) atom. There are eight inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(12), one O(3), one O(5), one O(9), and one F(2) atom to form FeO5F octahedra that share corners with three equivalent Fe(7)O5 trigonal bipyramids,  an edgeedge with one Fe(4)O5F octahedra, and  an edgeedge with one Fe(2)O6 octahedra. In the second Fe site, Fe(2) is bonded to one O(1), one O(10), one O(12), one O(13), one O(4), and one O(6) atom to form edge-sharing FeO6 octahedra. In the third Fe site, Fe(3) is bonded to one O(13), one O(14), one O(2), one O(4), one O(7), and one F(1) atom to form FeO5F octahedra that share  an edgeedge with one Fe(4)O5F octahedra and  an edgeedge with one Fe(2)O6 octahedra. In the fourth Fe site, Fe(4) is bonded to one O(11), one O(14), one O(2), one O(3), one O(8), and one F(2) atom to form FeO5F octahedra that share corners with three equivalent Fe(7)O5 trigonal bipyramids,  an edgeedge with one Fe(1)O5F octahedra, and  an edgeedge with one Fe(3)O5F octahedra. In the fifth Fe site, Fe(5) is bonded in a 5-coordinate geometry to one O(1), one O(10), one O(5), one O(6), and one O(9) atom. In the sixth Fe site, Fe(6) is bonded in a 5-coordinate geometry to one O(11), one O(14), one O(7), one O(8), and one F(1) atom. In the seventh Fe site, Fe(7) is bonded to one O(11), one O(3), one O(5), one O(8), and one O(9) atom to form distorted corner-sharing FeO5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 46-51°. In the eighth Fe site, Fe(8) is bonded in a 5-coordinate geometry to one O(10), one O(4), one O(6), one O(7), and one F(1) atom. There are fourteen 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(5) atom. In the second O site, O(2) is bonded in a water-like geometry to one Fe(3) and one Fe(4) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(4), and one Fe(7) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(2), one Fe(3), and one Fe(8) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(5), and one Fe(7) atom. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(2), one Fe(5), and one Fe(8) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Fe(3), one Fe(6), and one Fe(8) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one Fe(4), one Fe(6), and one Fe(7) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(5), and one Fe(7) atom. In the tenth O site, O(10) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(2), one Fe(5), and one Fe(8) atom. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one Fe(4), one Fe(6), and one Fe(7) atom. In the twelfth O site, O(12) is bonded in a T-shaped geometry to one Mg(1), one Fe(1), and one Fe(2) atom. In the thirteenth O site, O(13) is bonded in a T-shaped geometry to one Mg(1), one Fe(2), and one Fe(3) atom. In the fourteenth O site, O(14) is bonded in a distorted T-shaped geometry to one Fe(3), one Fe(4), and one Fe(6) atom. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Fe(3), one Fe(6), and one Fe(8) atom. In the second F site, F(2) is bonded in an L-shaped geometry to one Fe(1) and one Fe(4) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgFe8(O7F)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.173
_cell_length_b   5.175
_cell_length_c   11.605
_cell_angle_alpha   90.645
_cell_angle_beta   89.401
_cell_angle_gamma   102.090
_symmetry_Int_Tables_number   1
_cell_volume   303.739
_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  0.699  0.294  0.256  1.0
  Fe  Fe1  1  0.006  0.990  0.998  1.0
  Fe  Fe2  1  0.031  0.964  0.251  1.0
  Fe  Fe3  1  0.029  0.022  0.503  1.0
  Fe  Fe4  1  0.003  0.984  0.749  1.0
  Fe  Fe5  1  0.419  0.579  0.119  1.0
  Fe  Fe6  1  0.581  0.394  0.633  1.0
  Fe  Fe7  1  0.426  0.570  0.868  1.0
  Fe  Fe8  1  0.409  0.576  0.385  1.0
  O  O9  1  0.181  0.813  0.128  1.0
  O  O10  1  0.166  0.856  0.614  1.0
  O  O11  1  0.173  0.820  0.873  1.0
  O  O12  1  0.185  0.817  0.375  1.0
  O  O13  1  0.275  0.341  0.993  1.0
  O  O14  1  0.322  0.311  0.250  1.0
  O  O15  1  0.342  0.310  0.501  1.0
  O  O16  1  0.310  0.305  0.753  1.0
  O  O17  1  0.656  0.719  0.993  1.0
  O  O18  1  0.685  0.673  0.254  1.0
  O  O19  1  0.687  0.678  0.749  1.0
  O  O20  1  0.865  0.125  0.139  1.0
  O  O21  1  0.873  0.138  0.373  1.0
  O  O22  1  0.833  0.170  0.622  1.0
  F  F23  1  0.707  0.686  0.500  1.0
  F  F24  1  0.832  0.158  0.872  1.0
[/CIF]
.