The material structure described by Mg6NbFe crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 12-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Nb(1), and two equivalent Fe(1) atoms. In the second Mg site, Mg(2) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Fe(1) atoms to form distorted MgMg10Fe2 cuboctahedra that share corners with four equivalent Fe(1)Mg10Nb2 cuboctahedra, corners with six equivalent Mg(2)Mg10Fe2 cuboctahedra, edges with two equivalent Fe(1)Mg10Nb2 cuboctahedra, edges with four equivalent Mg(4)Mg10Nb2 cuboctahedra, edges with eight equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, faces with two equivalent Mg(2)Mg10Fe2 cuboctahedra, faces with two equivalent Mg(4)Mg10Nb2 cuboctahedra, faces with two equivalent Fe(1)Mg10Nb2 cuboctahedra, faces with four equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, and faces with six equivalent Nb(1)Mg10Fe2 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Nb(1), and two equivalent Fe(1) atoms to form distorted MgMg8Nb2Fe2 cuboctahedra that share corners with four equivalent Mg(4)Mg10Nb2 cuboctahedra, corners with four equivalent Nb(1)Mg10Fe2 cuboctahedra, corners with ten equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, edges with two equivalent Mg(4)Mg10Nb2 cuboctahedra, edges with two equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, edges with two equivalent Nb(1)Mg10Fe2 cuboctahedra, edges with four equivalent Mg(2)Mg10Fe2 cuboctahedra, edges with four equivalent Fe(1)Mg10Nb2 cuboctahedra, faces with two equivalent Mg(2)Mg10Fe2 cuboctahedra, faces with two equivalent Mg(4)Mg10Nb2 cuboctahedra, faces with two equivalent Nb(1)Mg10Fe2 cuboctahedra, faces with two equivalent Fe(1)Mg10Nb2 cuboctahedra, and faces with four equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(2), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Nb(1) atoms to form distorted MgMg10Nb2 cuboctahedra that share corners with four equivalent Nb(1)Mg10Fe2 cuboctahedra, corners with six equivalent Mg(4)Mg10Nb2 cuboctahedra, corners with eight equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, edges with two equivalent Nb(1)Mg10Fe2 cuboctahedra, edges with four equivalent Mg(2)Mg10Fe2 cuboctahedra, edges with four equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, faces with two equivalent Mg(2)Mg10Fe2 cuboctahedra, faces with two equivalent Mg(4)Mg10Nb2 cuboctahedra, faces with two equivalent Nb(1)Mg10Fe2 cuboctahedra, faces with four equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, and faces with six equivalent Fe(1)Mg10Nb2 cuboctahedra. Nb(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Fe(1) atoms to form distorted NbMg10Fe2 cuboctahedra that share corners with four equivalent Mg(4)Mg10Nb2 cuboctahedra, corners with six equivalent Nb(1)Mg10Fe2 cuboctahedra, corners with eight equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, edges with two equivalent Mg(4)Mg10Nb2 cuboctahedra, edges with four equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, edges with four equivalent Fe(1)Mg10Nb2 cuboctahedra, faces with two equivalent Mg(4)Mg10Nb2 cuboctahedra, faces with two equivalent Nb(1)Mg10Fe2 cuboctahedra, faces with two equivalent Fe(1)Mg10Nb2 cuboctahedra, faces with four equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, and faces with six equivalent Mg(2)Mg10Fe2 cuboctahedra. Fe(1) is bonded to two equivalent Mg(2), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Nb(1) atoms to form distorted FeMg10Nb2 cuboctahedra that share corners with four equivalent Mg(2)Mg10Fe2 cuboctahedra, corners with six equivalent Fe(1)Mg10Nb2 cuboctahedra, edges with two equivalent Mg(2)Mg10Fe2 cuboctahedra, edges with four equivalent Nb(1)Mg10Fe2 cuboctahedra, edges with eight equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, faces with two equivalent Mg(2)Mg10Fe2 cuboctahedra, faces with two equivalent Nb(1)Mg10Fe2 cuboctahedra, faces with two equivalent Fe(1)Mg10Nb2 cuboctahedra, faces with four equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, and faces with six equivalent Mg(4)Mg10Nb2 cuboctahedra. is represented by the CIF file [CIF]
data_Mg6NbFe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.673
_cell_length_b   5.968
_cell_length_c   6.203
_cell_angle_alpha   118.752
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   151.664
_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
  Fe  Fe0  1  0.000  0.804  0.607  1.0
  Mg  Mg1  1  0.000  0.820  0.161  1.0
  Mg  Mg2  1  0.000  0.340  0.161  1.0
  Mg  Mg3  1  0.000  0.328  0.656  1.0
  Mg  Mg4  1  0.500  0.683  0.847  1.0
  Mg  Mg5  1  0.500  0.164  0.847  1.0
  Mg  Mg6  1  0.500  0.168  0.336  1.0
  Nb  Nb7  1  0.500  0.693  0.385  1.0
[/CIF]
.
The material structure described by Mg6NbFe crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 12-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Nb(1), and two equivalent Fe(1) atoms. In the second Mg site, Mg(2) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Fe(1) atoms to form distorted MgMg10Fe2 cuboctahedra that share corners with four equivalent Fe(1)Mg10Nb2 cuboctahedra, corners with six equivalent Mg(2)Mg10Fe2 cuboctahedra, edges with two equivalent Fe(1)Mg10Nb2 cuboctahedra, edges with four equivalent Mg(4)Mg10Nb2 cuboctahedra, edges with eight equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, faces with two equivalent Mg(2)Mg10Fe2 cuboctahedra, faces with two equivalent Mg(4)Mg10Nb2 cuboctahedra, faces with two equivalent Fe(1)Mg10Nb2 cuboctahedra, faces with four equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, and faces with six equivalent Nb(1)Mg10Fe2 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Nb(1), and two equivalent Fe(1) atoms to form distorted MgMg8Nb2Fe2 cuboctahedra that share corners with four equivalent Mg(4)Mg10Nb2 cuboctahedra, corners with four equivalent Nb(1)Mg10Fe2 cuboctahedra, corners with ten equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, edges with two equivalent Mg(4)Mg10Nb2 cuboctahedra, edges with two equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, edges with two equivalent Nb(1)Mg10Fe2 cuboctahedra, edges with four equivalent Mg(2)Mg10Fe2 cuboctahedra, edges with four equivalent Fe(1)Mg10Nb2 cuboctahedra, faces with two equivalent Mg(2)Mg10Fe2 cuboctahedra, faces with two equivalent Mg(4)Mg10Nb2 cuboctahedra, faces with two equivalent Nb(1)Mg10Fe2 cuboctahedra, faces with two equivalent Fe(1)Mg10Nb2 cuboctahedra, and faces with four equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(2), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Nb(1) atoms to form distorted MgMg10Nb2 cuboctahedra that share corners with four equivalent Nb(1)Mg10Fe2 cuboctahedra, corners with six equivalent Mg(4)Mg10Nb2 cuboctahedra, corners with eight equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, edges with two equivalent Nb(1)Mg10Fe2 cuboctahedra, edges with four equivalent Mg(2)Mg10Fe2 cuboctahedra, edges with four equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, faces with two equivalent Mg(2)Mg10Fe2 cuboctahedra, faces with two equivalent Mg(4)Mg10Nb2 cuboctahedra, faces with two equivalent Nb(1)Mg10Fe2 cuboctahedra, faces with four equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, and faces with six equivalent Fe(1)Mg10Nb2 cuboctahedra. Nb(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Fe(1) atoms to form distorted NbMg10Fe2 cuboctahedra that share corners with four equivalent Mg(4)Mg10Nb2 cuboctahedra, corners with six equivalent Nb(1)Mg10Fe2 cuboctahedra, corners with eight equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, edges with two equivalent Mg(4)Mg10Nb2 cuboctahedra, edges with four equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, edges with four equivalent Fe(1)Mg10Nb2 cuboctahedra, faces with two equivalent Mg(4)Mg10Nb2 cuboctahedra, faces with two equivalent Nb(1)Mg10Fe2 cuboctahedra, faces with two equivalent Fe(1)Mg10Nb2 cuboctahedra, faces with four equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, and faces with six equivalent Mg(2)Mg10Fe2 cuboctahedra. Fe(1) is bonded to two equivalent Mg(2), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Nb(1) atoms to form distorted FeMg10Nb2 cuboctahedra that share corners with four equivalent Mg(2)Mg10Fe2 cuboctahedra, corners with six equivalent Fe(1)Mg10Nb2 cuboctahedra, edges with two equivalent Mg(2)Mg10Fe2 cuboctahedra, edges with four equivalent Nb(1)Mg10Fe2 cuboctahedra, edges with eight equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, faces with two equivalent Mg(2)Mg10Fe2 cuboctahedra, faces with two equivalent Nb(1)Mg10Fe2 cuboctahedra, faces with two equivalent Fe(1)Mg10Nb2 cuboctahedra, faces with four equivalent Mg(3)Mg8Nb2Fe2 cuboctahedra, and faces with six equivalent Mg(4)Mg10Nb2 cuboctahedra. is represented by the CIF file [CIF]
data_Mg6NbFe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.673
_cell_length_b   5.968
_cell_length_c   6.203
_cell_angle_alpha   118.752
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   151.664
_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
  Fe  Fe0  1  0.000  0.804  0.607  1.0
  Mg  Mg1  1  0.000  0.820  0.161  1.0
  Mg  Mg2  1  0.000  0.340  0.161  1.0
  Mg  Mg3  1  0.000  0.328  0.656  1.0
  Mg  Mg4  1  0.500  0.683  0.847  1.0
  Mg  Mg5  1  0.500  0.164  0.847  1.0
  Mg  Mg6  1  0.500  0.168  0.336  1.0
  Nb  Nb7  1  0.500  0.693  0.385  1.0
[/CIF]
.