data_Mg2Fe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.87
_cell_length_b   7.92
_cell_length_c   2.82
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2Fe
_chemical_formula_sum   'Mg4 Fe2'
_cell_volume   109.03
_cell_formula_units_Z   2
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  Mg2  1  0.61  0.36  0.0  1.0
  Mg  Mg3  1  0.26  0.56  0.0  1.0
  Mg  Mg4  1  0.05  0.52  0.41  1.0
  Mg  Mg5  1  0.83  0.4  0.41  1.0
  Fe  Fe0  1  0.0  0.0  0.0  1.0
  Fe  Fe1  1  0.44  0.96  0.41  1.0

data_Mg2Fe
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.82
_cell_length_b   4.87
_cell_length_c   7.92
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2Fe
_chemical_formula_sum   'Mg4 Fe2'
_cell_volume   109.03
_cell_formula_units_Z   2
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  0.0  0.26  0.56  1.0
  Mg  Mg1  1  0.0  0.61  0.36  1.0
  Mg  Mg2  1  0.41  0.05  0.52  1.0
  Mg  Mg3  1  0.41  0.83  0.4  1.0
  Fe  Fe4  1  0.0  0.0  0.0  1.0
  Fe  Fe5  1  0.41  0.44  0.96  1.0

Mg Mg Mg Mg Fe Fe
Mg Mg Mg Mg Fe Fe 0 3 o o o 1 2 o o o 2 3 - o o 4 5 - - o 4 5 o - - 4 5 o - o 4 4 o o + 5 5 o o + 
Mg2Fe crystallizes in the triclinic P1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 3-coordinate geometry to one Mg(2), two equivalent Mg(4), one Fe(1), and one Fe(2) atom. The Mg(1)-Mg(2) bond length is 2.33 Å. There is one shorter (1.61 Å) and one longer (2.00 Å) Mg(1)-Mg(4) bond length. The Mg(1)-Fe(1) bond length is 3.42 Å. The Mg(1)-Fe(2) bond length is 3.47 Å. In the second Mg site, Mg(2) is bonded in a 3-coordinate geometry to one Mg(1), two equivalent Mg(3), and one Fe(2) atom. There is one shorter (1.61 Å) and one longer (2.00 Å) Mg(2)-Mg(3) bond length. The Mg(2)-Fe(2) bond length is 3.47 Å. In the third Mg site, Mg(3) is bonded in a distorted trigonal planar geometry to one Mg(4) and two equivalent Mg(2) atoms. The Mg(3)-Mg(4) bond length is 1.45 Å. In the fourth Mg site, Mg(4) is bonded in a 3-coordinate geometry to one Mg(3), two equivalent Mg(1), and one Fe(1) atom. The Mg(4)-Fe(1) bond length is 3.47 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 8-coordinate geometry to one Mg(1), one Mg(4), two equivalent Fe(1), and four equivalent Fe(2) atoms. Both Fe(1)-Fe(1) bond lengths are 2.82 Å. There are a spread of Fe(1)-Fe(2) bond distances ranging from 2.45-3.22 Å. In the second Fe site, Fe(2) is bonded in a 8-coordinate geometry to one Mg(1), one Mg(2), two equivalent Fe(2), and four equivalent Fe(1) atoms. Both Fe(2)-Fe(2) bond lengths are 2.82 Å.