The compound described by Mg6FeSb is beta Cu3Ti-derived structured and 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 Fe(1), and two equivalent Sb(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)Mg10Sb2 cuboctahedra, corners with six equivalent Mg(2)Mg10Fe2 cuboctahedra, edges with two equivalent Fe(1)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Mg(2)Mg10Fe2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Fe(1)Mg10Sb2 cuboctahedra, and faces with six equivalent Sb(1)Mg10Fe2 cuboctahedra. In the third Mg site, Mg(3) is bonded in a 4-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), two equivalent Fe(1), and two equivalent Sb(1) atoms. 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 Sb(1) atoms to form distorted MgMg10Sb2 cuboctahedra that share corners with four equivalent Sb(1)Mg10Fe2 cuboctahedra, corners with six equivalent Mg(4)Mg10Sb2 cuboctahedra, edges with two equivalent Sb(1)Mg10Fe2 cuboctahedra, edges with four equivalent Mg(2)Mg10Fe2 cuboctahedra, faces with two equivalent Mg(2)Mg10Fe2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Mg10Fe2 cuboctahedra, and faces with six equivalent Fe(1)Mg10Sb2 cuboctahedra. Fe(1) is bonded to two equivalent Mg(2), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Sb(1) atoms to form FeMg10Sb2 cuboctahedra that share corners with four equivalent Mg(2)Mg10Fe2 cuboctahedra, corners with six equivalent Fe(1)Mg10Sb2 cuboctahedra, edges with two equivalent Mg(2)Mg10Fe2 cuboctahedra, edges with four equivalent Sb(1)Mg10Fe2 cuboctahedra, faces with two equivalent Mg(2)Mg10Fe2 cuboctahedra, faces with two equivalent Fe(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Mg10Fe2 cuboctahedra, and faces with six equivalent Mg(4)Mg10Sb2 cuboctahedra. Sb(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Fe(1) atoms to form SbMg10Fe2 cuboctahedra that share corners with four equivalent Mg(4)Mg10Sb2 cuboctahedra, corners with six equivalent Sb(1)Mg10Fe2 cuboctahedra, edges with two equivalent Mg(4)Mg10Sb2 cuboctahedra, edges with four equivalent Fe(1)Mg10Sb2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Fe(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Mg10Fe2 cuboctahedra, and faces with six equivalent Mg(2)Mg10Fe2 cuboctahedra. is represented by the CIF file [CIF]
data_Mg6FeSb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.849
_cell_length_b   6.126
_cell_length_c   6.126
_cell_angle_alpha   118.473
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   159.974
_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  0.168  0.832  1.0
  Mg  Mg1  1  1.000  0.676  0.839  1.0
  Mg  Mg2  1  1.000  0.161  0.324  1.0
  Mg  Mg3  1  0.000  0.664  0.336  1.0
  Mg  Mg4  1  0.500  0.852  0.676  1.0
  Mg  Mg5  1  0.500  0.324  0.148  1.0
  Mg  Mg6  1  0.500  0.830  0.170  1.0
  Sb  Sb7  1  0.500  0.324  0.676  1.0
[/CIF]
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The compound described by Mg6FeSb is beta Cu3Ti-derived structured and 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 Fe(1), and two equivalent Sb(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)Mg10Sb2 cuboctahedra, corners with six equivalent Mg(2)Mg10Fe2 cuboctahedra, edges with two equivalent Fe(1)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Mg(2)Mg10Fe2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Fe(1)Mg10Sb2 cuboctahedra, and faces with six equivalent Sb(1)Mg10Fe2 cuboctahedra. In the third Mg site, Mg(3) is bonded in a 4-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), two equivalent Fe(1), and two equivalent Sb(1) atoms. 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 Sb(1) atoms to form distorted MgMg10Sb2 cuboctahedra that share corners with four equivalent Sb(1)Mg10Fe2 cuboctahedra, corners with six equivalent Mg(4)Mg10Sb2 cuboctahedra, edges with two equivalent Sb(1)Mg10Fe2 cuboctahedra, edges with four equivalent Mg(2)Mg10Fe2 cuboctahedra, faces with two equivalent Mg(2)Mg10Fe2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Mg10Fe2 cuboctahedra, and faces with six equivalent Fe(1)Mg10Sb2 cuboctahedra. Fe(1) is bonded to two equivalent Mg(2), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Sb(1) atoms to form FeMg10Sb2 cuboctahedra that share corners with four equivalent Mg(2)Mg10Fe2 cuboctahedra, corners with six equivalent Fe(1)Mg10Sb2 cuboctahedra, edges with two equivalent Mg(2)Mg10Fe2 cuboctahedra, edges with four equivalent Sb(1)Mg10Fe2 cuboctahedra, faces with two equivalent Mg(2)Mg10Fe2 cuboctahedra, faces with two equivalent Fe(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Mg10Fe2 cuboctahedra, and faces with six equivalent Mg(4)Mg10Sb2 cuboctahedra. Sb(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Fe(1) atoms to form SbMg10Fe2 cuboctahedra that share corners with four equivalent Mg(4)Mg10Sb2 cuboctahedra, corners with six equivalent Sb(1)Mg10Fe2 cuboctahedra, edges with two equivalent Mg(4)Mg10Sb2 cuboctahedra, edges with four equivalent Fe(1)Mg10Sb2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Fe(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Mg10Fe2 cuboctahedra, and faces with six equivalent Mg(2)Mg10Fe2 cuboctahedra. is represented by the CIF file [CIF]
data_Mg6FeSb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.849
_cell_length_b   6.126
_cell_length_c   6.126
_cell_angle_alpha   118.473
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   159.974
_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  0.168  0.832  1.0
  Mg  Mg1  1  1.000  0.676  0.839  1.0
  Mg  Mg2  1  1.000  0.161  0.324  1.0
  Mg  Mg3  1  0.000  0.664  0.336  1.0
  Mg  Mg4  1  0.500  0.852  0.676  1.0
  Mg  Mg5  1  0.500  0.324  0.148  1.0
  Mg  Mg6  1  0.500  0.830  0.170  1.0
  Sb  Sb7  1  0.500  0.324  0.676  1.0
[/CIF]
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