The material described by Mg6YSb 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 Y(1), and two equivalent Sb(1) atoms to form distorted MgY2Mg8Sb2 cuboctahedra that share corners with four equivalent Y(1)Mg10Sb2 cuboctahedra, corners with four equivalent Sb(1)Y2Mg10 cuboctahedra, corners with ten equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, edges with two equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, edges with two equivalent Y(1)Mg10Sb2 cuboctahedra, edges with two equivalent Sb(1)Y2Mg10 cuboctahedra, edges with four equivalent Mg(4)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(3)Y2Mg10 cuboctahedra, edges with four equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, and faces with eight equivalent Mg(2)Y2Mg8Sb2 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Y(1), and two equivalent Sb(1) atoms to form distorted MgY2Mg8Sb2 cuboctahedra that share corners with four equivalent Mg(4)Mg10Sb2 cuboctahedra, corners with four equivalent Mg(3)Y2Mg10 cuboctahedra, corners with ten equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, edges with two equivalent Mg(4)Mg10Sb2 cuboctahedra, edges with two equivalent Mg(3)Y2Mg10 cuboctahedra, edges with two equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, edges with four equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, edges with four equivalent Y(1)Mg10Sb2 cuboctahedra, edges with four equivalent Sb(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, and faces with eight equivalent Mg(1)Y2Mg8Sb2 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Y(1) atoms to form MgY2Mg10 cuboctahedra that share corners with four equivalent Mg(4)Mg10Sb2 cuboctahedra, corners with six equivalent Mg(3)Y2Mg10 cuboctahedra, corners with eight equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, edges with two equivalent Mg(4)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, edges with four equivalent Y(1)Mg10Sb2 cuboctahedra, edges with eight equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Mg10Sb2 cuboctahedra, faces with four equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, faces with four equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, and faces with six equivalent Sb(1)Y2Mg10 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 Sb(1) atoms to form distorted MgMg10Sb2 cuboctahedra that share corners with four equivalent Mg(3)Y2Mg10 cuboctahedra, corners with six equivalent Mg(4)Mg10Sb2 cuboctahedra, corners with eight equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, edges with two equivalent Mg(3)Y2Mg10 cuboctahedra, edges with four equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, edges with four equivalent Sb(1)Y2Mg10 cuboctahedra, edges with eight equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Sb(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, faces with four equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, and faces with six equivalent Y(1)Mg10Sb2 cuboctahedra. Y(1) is bonded to two equivalent Mg(3), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Sb(1) atoms to form distorted YMg10Sb2 cuboctahedra that share corners with four equivalent Sb(1)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)Mg10Sb2 cuboctahedra, corners with eight equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, edges with two equivalent Sb(1)Y2Mg10 cuboctahedra, edges with four equivalent Mg(3)Y2Mg10 cuboctahedra, edges with four equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, edges with eight equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, faces with four equivalent Mg(2)Y2Mg8Sb2 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(2), and two equivalent Y(1) atoms to form SbY2Mg10 cuboctahedra that share corners with four equivalent Y(1)Mg10Sb2 cuboctahedra, corners with six equivalent Sb(1)Y2Mg10 cuboctahedra, corners with eight equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, edges with two equivalent Y(1)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(4)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, edges with eight equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Y(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, faces with four equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, and faces with six equivalent Mg(3)Y2Mg10 cuboctahedra. is represented by the CIF card [CIF]
data_YMg6Sb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.382
_cell_length_b   6.229
_cell_length_c   6.587
_cell_angle_alpha   118.215
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   194.606
_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  0.500  0.666  0.835  1.0
  Mg  Mg1  1  0.500  0.169  0.835  1.0
  Mg  Mg2  1  0.000  0.827  0.156  1.0
  Mg  Mg3  1  1.000  0.329  0.156  1.0
  Mg  Mg4  1  0.000  0.336  0.672  1.0
  Mg  Mg5  1  0.000  0.836  0.671  1.0
  Sb  Sb6  1  0.500  0.666  0.333  1.0
  Y  Y7  1  0.500  0.171  0.341  1.0
[/CIF]
.
The material described by Mg6YSb 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 Y(1), and two equivalent Sb(1) atoms to form distorted MgY2Mg8Sb2 cuboctahedra that share corners with four equivalent Y(1)Mg10Sb2 cuboctahedra, corners with four equivalent Sb(1)Y2Mg10 cuboctahedra, corners with ten equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, edges with two equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, edges with two equivalent Y(1)Mg10Sb2 cuboctahedra, edges with two equivalent Sb(1)Y2Mg10 cuboctahedra, edges with four equivalent Mg(4)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(3)Y2Mg10 cuboctahedra, edges with four equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, and faces with eight equivalent Mg(2)Y2Mg8Sb2 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), two equivalent Y(1), and two equivalent Sb(1) atoms to form distorted MgY2Mg8Sb2 cuboctahedra that share corners with four equivalent Mg(4)Mg10Sb2 cuboctahedra, corners with four equivalent Mg(3)Y2Mg10 cuboctahedra, corners with ten equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, edges with two equivalent Mg(4)Mg10Sb2 cuboctahedra, edges with two equivalent Mg(3)Y2Mg10 cuboctahedra, edges with two equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, edges with four equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, edges with four equivalent Y(1)Mg10Sb2 cuboctahedra, edges with four equivalent Sb(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, and faces with eight equivalent Mg(1)Y2Mg8Sb2 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Y(1) atoms to form MgY2Mg10 cuboctahedra that share corners with four equivalent Mg(4)Mg10Sb2 cuboctahedra, corners with six equivalent Mg(3)Y2Mg10 cuboctahedra, corners with eight equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, edges with two equivalent Mg(4)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, edges with four equivalent Y(1)Mg10Sb2 cuboctahedra, edges with eight equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Mg10Sb2 cuboctahedra, faces with four equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, faces with four equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, and faces with six equivalent Sb(1)Y2Mg10 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 Sb(1) atoms to form distorted MgMg10Sb2 cuboctahedra that share corners with four equivalent Mg(3)Y2Mg10 cuboctahedra, corners with six equivalent Mg(4)Mg10Sb2 cuboctahedra, corners with eight equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, edges with two equivalent Mg(3)Y2Mg10 cuboctahedra, edges with four equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, edges with four equivalent Sb(1)Y2Mg10 cuboctahedra, edges with eight equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Sb(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, faces with four equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, and faces with six equivalent Y(1)Mg10Sb2 cuboctahedra. Y(1) is bonded to two equivalent Mg(3), four equivalent Mg(1), four equivalent Mg(2), and two equivalent Sb(1) atoms to form distorted YMg10Sb2 cuboctahedra that share corners with four equivalent Sb(1)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)Mg10Sb2 cuboctahedra, corners with eight equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, edges with two equivalent Sb(1)Y2Mg10 cuboctahedra, edges with four equivalent Mg(3)Y2Mg10 cuboctahedra, edges with four equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, edges with eight equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, faces with four equivalent Mg(2)Y2Mg8Sb2 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(2), and two equivalent Y(1) atoms to form SbY2Mg10 cuboctahedra that share corners with four equivalent Y(1)Mg10Sb2 cuboctahedra, corners with six equivalent Sb(1)Y2Mg10 cuboctahedra, corners with eight equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, edges with two equivalent Y(1)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(4)Mg10Sb2 cuboctahedra, edges with four equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, edges with eight equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, faces with two equivalent Mg(4)Mg10Sb2 cuboctahedra, faces with two equivalent Y(1)Mg10Sb2 cuboctahedra, faces with two equivalent Sb(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(1)Y2Mg8Sb2 cuboctahedra, faces with four equivalent Mg(2)Y2Mg8Sb2 cuboctahedra, and faces with six equivalent Mg(3)Y2Mg10 cuboctahedra. is represented by the CIF card [CIF]
data_YMg6Sb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.382
_cell_length_b   6.229
_cell_length_c   6.587
_cell_angle_alpha   118.215
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   194.606
_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  0.500  0.666  0.835  1.0
  Mg  Mg1  1  0.500  0.169  0.835  1.0
  Mg  Mg2  1  0.000  0.827  0.156  1.0
  Mg  Mg3  1  1.000  0.329  0.156  1.0
  Mg  Mg4  1  0.000  0.336  0.672  1.0
  Mg  Mg5  1  0.000  0.836  0.671  1.0
  Sb  Sb6  1  0.500  0.666  0.333  1.0
  Y  Y7  1  0.500  0.171  0.341  1.0
[/CIF]
.