The structure described by Mg6BiSb crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Bi(1), and two equivalent Sb(1) atoms to form distorted MgMg8Bi2Sb2 cuboctahedra that share corners with two equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, corners with two equivalent Mg(3)Mg6Sb2 cuboctahedra, corners with four equivalent Bi(1)Mg10Sb2 cuboctahedra, corners with four equivalent Sb(1)Mg10Bi2 cuboctahedra, corners with ten equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, edges with two equivalent Mg(3)Mg6Sb2 cuboctahedra, edges with two equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, edges with two equivalent Bi(1)Mg10Sb2 cuboctahedra, edges with two equivalent Sb(1)Mg10Bi2 cuboctahedra, edges with four equivalent Mg(4)Mg10Bi2 cuboctahedra, edges with four equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, faces with two equivalent Mg(4)Mg10Bi2 cuboctahedra, faces with two equivalent Mg(3)Mg6Sb2 cuboctahedra, faces with two equivalent Bi(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Mg10Bi2 cuboctahedra, faces with four equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, and faces with six equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1), two equivalent Mg(4), two equivalent Bi(1), and two equivalent Sb(1) atoms to form distorted MgMg4Bi2Sb2 cuboctahedra that share corners with two equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, corners with two equivalent Bi(1)Mg10Sb2 cuboctahedra, corners with four equivalent Mg(4)Mg10Bi2 cuboctahedra, corners with four equivalent Sb(1)Mg10Bi2 cuboctahedra, corners with six equivalent Mg(3)Mg6Sb2 cuboctahedra, corners with eight equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, edges with two equivalent Mg(4)Mg10Bi2 cuboctahedra, edges with two equivalent Bi(1)Mg10Sb2 cuboctahedra, edges with two equivalent Sb(1)Mg10Bi2 cuboctahedra, edges with four equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, faces with two equivalent Mg(3)Mg6Sb2 cuboctahedra, faces with two equivalent Bi(1)Mg10Sb2 cuboctahedra, faces with four equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, and faces with six equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(4), four equivalent Mg(1), and two equivalent Sb(1) atoms to form distorted MgMg6Sb2 cuboctahedra that share corners with two equivalent Mg(3)Mg6Sb2 cuboctahedra, corners with four equivalent Mg(4)Mg10Bi2 cuboctahedra, corners with four equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, corners with four equivalent Sb(1)Mg10Bi2 cuboctahedra, corners with twelve equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, edges with two equivalent Mg(4)Mg10Bi2 cuboctahedra, edges with two equivalent Bi(1)Mg10Sb2 cuboctahedra, edges with two equivalent Sb(1)Mg10Bi2 cuboctahedra, edges with four equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, faces with two equivalent Mg(3)Mg6Sb2 cuboctahedra, faces with four equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, faces with four equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, and faces with four equivalent Bi(1)Mg10Sb2 cuboctahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(3), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Bi(1) atoms to form distorted MgMg10Bi2 cuboctahedra that share corners with four equivalent Mg(3)Mg6Sb2 cuboctahedra, corners with six equivalent Mg(4)Mg10Bi2 cuboctahedra, corners with eight equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, edges with two equivalent Mg(3)Mg6Sb2 cuboctahedra, edges with four equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, edges with four equivalent Bi(1)Mg10Sb2 cuboctahedra, edges with eight equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, faces with two equivalent Mg(4)Mg10Bi2 cuboctahedra, faces with two equivalent Bi(1)Mg10Sb2 cuboctahedra, faces with four equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, and faces with six equivalent Sb(1)Mg10Bi2 cuboctahedra. Bi(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Sb(1) atoms to form BiMg10Sb2 cuboctahedra that share corners with four equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, corners with four equivalent Sb(1)Mg10Bi2 cuboctahedra, corners with six equivalent Bi(1)Mg10Sb2 cuboctahedra, corners with eight equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, edges with two equivalent Mg(3)Mg6Sb2 cuboctahedra, edges with two equivalent Sb(1)Mg10Bi2 cuboctahedra, edges with four equivalent Mg(4)Mg10Bi2 cuboctahedra, edges with four equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, edges with four equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, faces with two equivalent Mg(4)Mg10Bi2 cuboctahedra, faces with two equivalent Bi(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Mg10Bi2 cuboctahedra, faces with four equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, faces with four equivalent Mg(3)Mg6Sb2 cuboctahedra, and faces with four equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra. Sb(1) is bonded to two equivalent Mg(3), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Bi(1) atoms to form SbMg10Bi2 cuboctahedra that share corners with four equivalent Mg(3)Mg6Sb2 cuboctahedra, corners with four equivalent Bi(1)Mg10Sb2 cuboctahedra, corners with six equivalent Sb(1)Mg10Bi2 cuboctahedra, corners with eight equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, corners with eight equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, edges with two equivalent Mg(3)Mg6Sb2 cuboctahedra, edges with two equivalent Bi(1)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, edges with four equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, faces with two equivalent Bi(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Mg10Bi2 cuboctahedra, faces with four equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, and faces with six equivalent Mg(4)Mg10Bi2 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg6BiSb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.313
_cell_length_b   6.518
_cell_length_c   6.553
_cell_angle_alpha   119.825
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   196.854
_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
  Bi  Bi0  1  0.500  0.667  0.335  1.0
  Mg  Mg1  1  0.500  0.667  0.832  1.0
  Mg  Mg2  1  0.500  0.166  0.832  1.0
  Mg  Mg3  1  0.000  0.835  0.161  1.0
  Mg  Mg4  1  1.000  0.326  0.161  1.0
  Mg  Mg5  1  0.000  0.335  0.669  1.0
  Mg  Mg6  1  0.000  0.837  0.675  1.0
  Sb  Sb7  1  0.500  0.168  0.335  1.0
[/CIF]
.
The structure described by Mg6BiSb crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Bi(1), and two equivalent Sb(1) atoms to form distorted MgMg8Bi2Sb2 cuboctahedra that share corners with two equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, corners with two equivalent Mg(3)Mg6Sb2 cuboctahedra, corners with four equivalent Bi(1)Mg10Sb2 cuboctahedra, corners with four equivalent Sb(1)Mg10Bi2 cuboctahedra, corners with ten equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, edges with two equivalent Mg(3)Mg6Sb2 cuboctahedra, edges with two equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, edges with two equivalent Bi(1)Mg10Sb2 cuboctahedra, edges with two equivalent Sb(1)Mg10Bi2 cuboctahedra, edges with four equivalent Mg(4)Mg10Bi2 cuboctahedra, edges with four equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, faces with two equivalent Mg(4)Mg10Bi2 cuboctahedra, faces with two equivalent Mg(3)Mg6Sb2 cuboctahedra, faces with two equivalent Bi(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Mg10Bi2 cuboctahedra, faces with four equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, and faces with six equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1), two equivalent Mg(4), two equivalent Bi(1), and two equivalent Sb(1) atoms to form distorted MgMg4Bi2Sb2 cuboctahedra that share corners with two equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, corners with two equivalent Bi(1)Mg10Sb2 cuboctahedra, corners with four equivalent Mg(4)Mg10Bi2 cuboctahedra, corners with four equivalent Sb(1)Mg10Bi2 cuboctahedra, corners with six equivalent Mg(3)Mg6Sb2 cuboctahedra, corners with eight equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, edges with two equivalent Mg(4)Mg10Bi2 cuboctahedra, edges with two equivalent Bi(1)Mg10Sb2 cuboctahedra, edges with two equivalent Sb(1)Mg10Bi2 cuboctahedra, edges with four equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, faces with two equivalent Mg(3)Mg6Sb2 cuboctahedra, faces with two equivalent Bi(1)Mg10Sb2 cuboctahedra, faces with four equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, and faces with six equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(4), four equivalent Mg(1), and two equivalent Sb(1) atoms to form distorted MgMg6Sb2 cuboctahedra that share corners with two equivalent Mg(3)Mg6Sb2 cuboctahedra, corners with four equivalent Mg(4)Mg10Bi2 cuboctahedra, corners with four equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, corners with four equivalent Sb(1)Mg10Bi2 cuboctahedra, corners with twelve equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, edges with two equivalent Mg(4)Mg10Bi2 cuboctahedra, edges with two equivalent Bi(1)Mg10Sb2 cuboctahedra, edges with two equivalent Sb(1)Mg10Bi2 cuboctahedra, edges with four equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, faces with two equivalent Mg(3)Mg6Sb2 cuboctahedra, faces with four equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, faces with four equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, and faces with four equivalent Bi(1)Mg10Sb2 cuboctahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(3), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Bi(1) atoms to form distorted MgMg10Bi2 cuboctahedra that share corners with four equivalent Mg(3)Mg6Sb2 cuboctahedra, corners with six equivalent Mg(4)Mg10Bi2 cuboctahedra, corners with eight equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, edges with two equivalent Mg(3)Mg6Sb2 cuboctahedra, edges with four equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, edges with four equivalent Bi(1)Mg10Sb2 cuboctahedra, edges with eight equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, faces with two equivalent Mg(4)Mg10Bi2 cuboctahedra, faces with two equivalent Bi(1)Mg10Sb2 cuboctahedra, faces with four equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, and faces with six equivalent Sb(1)Mg10Bi2 cuboctahedra. Bi(1) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Sb(1) atoms to form BiMg10Sb2 cuboctahedra that share corners with four equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, corners with four equivalent Sb(1)Mg10Bi2 cuboctahedra, corners with six equivalent Bi(1)Mg10Sb2 cuboctahedra, corners with eight equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, edges with two equivalent Mg(3)Mg6Sb2 cuboctahedra, edges with two equivalent Sb(1)Mg10Bi2 cuboctahedra, edges with four equivalent Mg(4)Mg10Bi2 cuboctahedra, edges with four equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, edges with four equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, faces with two equivalent Mg(4)Mg10Bi2 cuboctahedra, faces with two equivalent Bi(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Mg10Bi2 cuboctahedra, faces with four equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, faces with four equivalent Mg(3)Mg6Sb2 cuboctahedra, and faces with four equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra. Sb(1) is bonded to two equivalent Mg(3), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Bi(1) atoms to form SbMg10Bi2 cuboctahedra that share corners with four equivalent Mg(3)Mg6Sb2 cuboctahedra, corners with four equivalent Bi(1)Mg10Sb2 cuboctahedra, corners with six equivalent Sb(1)Mg10Bi2 cuboctahedra, corners with eight equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, corners with eight equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, edges with two equivalent Mg(3)Mg6Sb2 cuboctahedra, edges with two equivalent Bi(1)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(2)Mg4Bi2Sb2 cuboctahedra, edges with four equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, faces with two equivalent Bi(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Mg10Bi2 cuboctahedra, faces with four equivalent Mg(1)Mg8Bi2Sb2 cuboctahedra, and faces with six equivalent Mg(4)Mg10Bi2 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg6BiSb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.313
_cell_length_b   6.518
_cell_length_c   6.553
_cell_angle_alpha   119.825
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   196.854
_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
  Bi  Bi0  1  0.500  0.667  0.335  1.0
  Mg  Mg1  1  0.500  0.667  0.832  1.0
  Mg  Mg2  1  0.500  0.166  0.832  1.0
  Mg  Mg3  1  0.000  0.835  0.161  1.0
  Mg  Mg4  1  1.000  0.326  0.161  1.0
  Mg  Mg5  1  0.000  0.335  0.669  1.0
  Mg  Mg6  1  0.000  0.837  0.675  1.0
  Sb  Sb7  1  0.500  0.168  0.335  1.0
[/CIF]
.