The compound described by Mg5Y crystallizes in the orthorhombic Amm2 space group. There are five 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), and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(1)Mg12 cuboctahedra, corners with six equivalent Mg(3)Y2Mg10 cuboctahedra, corners with six equivalent Mg(2)Y4Mg8 cuboctahedra, edges with three equivalent Mg(3)Y2Mg10 cuboctahedra, edges with three equivalent Mg(2)Y4Mg8 cuboctahedra, edges with four equivalent Mg(5)Y2Mg10 cuboctahedra, edges with eight equivalent Y(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y4Mg8 cuboctahedra, faces with two equivalent Y(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(1)Mg12 cuboctahedra, faces with four equivalent Mg(5)Y2Mg10 cuboctahedra, and faces with six equivalent Mg(4)Y2Mg10 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(5), and four equivalent Y(1) atoms to form MgY4Mg8 cuboctahedra that share corners with six equivalent Mg(1)Mg12 cuboctahedra, corners with six equivalent Mg(3)Y2Mg10 cuboctahedra, corners with six equivalent Mg(2)Y4Mg8 cuboctahedra, edges with three equivalent Mg(1)Mg12 cuboctahedra, edges with three equivalent Mg(3)Y2Mg10 cuboctahedra, edges with four equivalent Y(1)Y2Mg10 cuboctahedra, edges with eight equivalent Mg(4)Y2Mg10 cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Mg(4)Y2Mg10 cuboctahedra, faces with four equivalent Mg(2)Y4Mg8 cuboctahedra, faces with four equivalent Y(1)Y2Mg10 cuboctahedra, and faces with six equivalent Mg(5)Y2Mg10 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), four equivalent Mg(4), and two equivalent Y(1) atoms to form MgY2Mg10 cuboctahedra that share corners with six equivalent Mg(1)Mg12 cuboctahedra, corners with six equivalent Mg(3)Y2Mg10 cuboctahedra, corners with six equivalent Mg(2)Y4Mg8 cuboctahedra, edges with three equivalent Mg(1)Mg12 cuboctahedra, edges with three equivalent Mg(2)Y4Mg8 cuboctahedra, edges with four equivalent Mg(4)Y2Mg10 cuboctahedra, edges with eight equivalent Mg(5)Y2Mg10 cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(5)Y2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y4Mg8 cuboctahedra, faces with four equivalent Mg(3)Y2Mg10 cuboctahedra, faces with four equivalent Mg(4)Y2Mg10 cuboctahedra, and faces with six equivalent Y(1)Y2Mg10 cuboctahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(1), two equivalent Mg(4), two equivalent Mg(5), four equivalent Mg(3), and two equivalent Y(1) atoms to form MgY2Mg10 cuboctahedra that share corners with six equivalent Mg(4)Y2Mg10 cuboctahedra, corners with six equivalent Mg(5)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)Y2Mg10 cuboctahedra, edges with three equivalent Mg(5)Y2Mg10 cuboctahedra, edges with three equivalent Y(1)Y2Mg10 cuboctahedra, edges with four equivalent Mg(3)Y2Mg10 cuboctahedra, edges with eight equivalent Mg(2)Y4Mg8 cuboctahedra, faces with two equivalent Mg(5)Y2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y4Mg8 cuboctahedra, faces with two equivalent Y(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(3)Y2Mg10 cuboctahedra, faces with four equivalent Mg(4)Y2Mg10 cuboctahedra, and faces with six equivalent Mg(1)Mg12 cuboctahedra. In the fifth Mg site, Mg(5) is bonded to two equivalent Mg(2), two equivalent Mg(4), two equivalent Mg(5), four equivalent Mg(1), and two equivalent Y(1) atoms to form MgY2Mg10 cuboctahedra that share corners with six equivalent Mg(4)Y2Mg10 cuboctahedra, corners with six equivalent Mg(5)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)Y2Mg10 cuboctahedra, edges with three equivalent Mg(4)Y2Mg10 cuboctahedra, edges with three equivalent Y(1)Y2Mg10 cuboctahedra, edges with four equivalent Mg(1)Mg12 cuboctahedra, edges with eight equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Mg(4)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(1)Mg12 cuboctahedra, faces with four equivalent Mg(5)Y2Mg10 cuboctahedra, and faces with six equivalent Mg(2)Y4Mg8 cuboctahedra. Y(1) is bonded to two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(5), four equivalent Mg(2), and two equivalent Y(1) atoms to form YY2Mg10 cuboctahedra that share corners with six equivalent Mg(4)Y2Mg10 cuboctahedra, corners with six equivalent Mg(5)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)Y2Mg10 cuboctahedra, edges with three equivalent Mg(4)Y2Mg10 cuboctahedra, edges with three equivalent Mg(5)Y2Mg10 cuboctahedra, edges with four equivalent Mg(2)Y4Mg8 cuboctahedra, edges with eight equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(4)Y2Mg10 cuboctahedra, faces with two equivalent Mg(5)Y2Mg10 cuboctahedra, faces with four equivalent Mg(2)Y4Mg8 cuboctahedra, faces with four equivalent Y(1)Y2Mg10 cuboctahedra, and faces with six equivalent Mg(3)Y2Mg10 cuboctahedra. is represented by the CIF card [CIF]
data_YMg5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.670
_cell_length_b   8.670
_cell_length_c   5.257
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   158.141
_symmetry_Int_Tables_number   1
_cell_volume   147.106
_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
  Y  Y0  1  0.780  0.220  0.000  1.0
  Mg  Mg1  1  0.997  0.003  0.500  1.0
  Mg  Mg2  1  0.338  0.662  0.500  1.0
  Mg  Mg3  1  0.664  0.336  0.500  1.0
  Mg  Mg4  1  0.106  0.894  0.000  1.0
  Mg  Mg5  1  0.447  0.553  0.000  1.0
[/CIF]
.
The compound described by Mg5Y crystallizes in the orthorhombic Amm2 space group. There are five 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), and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(1)Mg12 cuboctahedra, corners with six equivalent Mg(3)Y2Mg10 cuboctahedra, corners with six equivalent Mg(2)Y4Mg8 cuboctahedra, edges with three equivalent Mg(3)Y2Mg10 cuboctahedra, edges with three equivalent Mg(2)Y4Mg8 cuboctahedra, edges with four equivalent Mg(5)Y2Mg10 cuboctahedra, edges with eight equivalent Y(1)Y2Mg10 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y4Mg8 cuboctahedra, faces with two equivalent Y(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(1)Mg12 cuboctahedra, faces with four equivalent Mg(5)Y2Mg10 cuboctahedra, and faces with six equivalent Mg(4)Y2Mg10 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(5), and four equivalent Y(1) atoms to form MgY4Mg8 cuboctahedra that share corners with six equivalent Mg(1)Mg12 cuboctahedra, corners with six equivalent Mg(3)Y2Mg10 cuboctahedra, corners with six equivalent Mg(2)Y4Mg8 cuboctahedra, edges with three equivalent Mg(1)Mg12 cuboctahedra, edges with three equivalent Mg(3)Y2Mg10 cuboctahedra, edges with four equivalent Y(1)Y2Mg10 cuboctahedra, edges with eight equivalent Mg(4)Y2Mg10 cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Mg(4)Y2Mg10 cuboctahedra, faces with four equivalent Mg(2)Y4Mg8 cuboctahedra, faces with four equivalent Y(1)Y2Mg10 cuboctahedra, and faces with six equivalent Mg(5)Y2Mg10 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), four equivalent Mg(4), and two equivalent Y(1) atoms to form MgY2Mg10 cuboctahedra that share corners with six equivalent Mg(1)Mg12 cuboctahedra, corners with six equivalent Mg(3)Y2Mg10 cuboctahedra, corners with six equivalent Mg(2)Y4Mg8 cuboctahedra, edges with three equivalent Mg(1)Mg12 cuboctahedra, edges with three equivalent Mg(2)Y4Mg8 cuboctahedra, edges with four equivalent Mg(4)Y2Mg10 cuboctahedra, edges with eight equivalent Mg(5)Y2Mg10 cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(5)Y2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y4Mg8 cuboctahedra, faces with four equivalent Mg(3)Y2Mg10 cuboctahedra, faces with four equivalent Mg(4)Y2Mg10 cuboctahedra, and faces with six equivalent Y(1)Y2Mg10 cuboctahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(1), two equivalent Mg(4), two equivalent Mg(5), four equivalent Mg(3), and two equivalent Y(1) atoms to form MgY2Mg10 cuboctahedra that share corners with six equivalent Mg(4)Y2Mg10 cuboctahedra, corners with six equivalent Mg(5)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)Y2Mg10 cuboctahedra, edges with three equivalent Mg(5)Y2Mg10 cuboctahedra, edges with three equivalent Y(1)Y2Mg10 cuboctahedra, edges with four equivalent Mg(3)Y2Mg10 cuboctahedra, edges with eight equivalent Mg(2)Y4Mg8 cuboctahedra, faces with two equivalent Mg(5)Y2Mg10 cuboctahedra, faces with two equivalent Mg(2)Y4Mg8 cuboctahedra, faces with two equivalent Y(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(3)Y2Mg10 cuboctahedra, faces with four equivalent Mg(4)Y2Mg10 cuboctahedra, and faces with six equivalent Mg(1)Mg12 cuboctahedra. In the fifth Mg site, Mg(5) is bonded to two equivalent Mg(2), two equivalent Mg(4), two equivalent Mg(5), four equivalent Mg(1), and two equivalent Y(1) atoms to form MgY2Mg10 cuboctahedra that share corners with six equivalent Mg(4)Y2Mg10 cuboctahedra, corners with six equivalent Mg(5)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)Y2Mg10 cuboctahedra, edges with three equivalent Mg(4)Y2Mg10 cuboctahedra, edges with three equivalent Y(1)Y2Mg10 cuboctahedra, edges with four equivalent Mg(1)Mg12 cuboctahedra, edges with eight equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Mg(3)Y2Mg10 cuboctahedra, faces with two equivalent Mg(4)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Y2Mg10 cuboctahedra, faces with four equivalent Mg(1)Mg12 cuboctahedra, faces with four equivalent Mg(5)Y2Mg10 cuboctahedra, and faces with six equivalent Mg(2)Y4Mg8 cuboctahedra. Y(1) is bonded to two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(5), four equivalent Mg(2), and two equivalent Y(1) atoms to form YY2Mg10 cuboctahedra that share corners with six equivalent Mg(4)Y2Mg10 cuboctahedra, corners with six equivalent Mg(5)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)Y2Mg10 cuboctahedra, edges with three equivalent Mg(4)Y2Mg10 cuboctahedra, edges with three equivalent Mg(5)Y2Mg10 cuboctahedra, edges with four equivalent Mg(2)Y4Mg8 cuboctahedra, edges with eight equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(4)Y2Mg10 cuboctahedra, faces with two equivalent Mg(5)Y2Mg10 cuboctahedra, faces with four equivalent Mg(2)Y4Mg8 cuboctahedra, faces with four equivalent Y(1)Y2Mg10 cuboctahedra, and faces with six equivalent Mg(3)Y2Mg10 cuboctahedra. is represented by the CIF card [CIF]
data_YMg5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.670
_cell_length_b   8.670
_cell_length_c   5.257
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   158.141
_symmetry_Int_Tables_number   1
_cell_volume   147.106
_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
  Y  Y0  1  0.780  0.220  0.000  1.0
  Mg  Mg1  1  0.997  0.003  0.500  1.0
  Mg  Mg2  1  0.338  0.662  0.500  1.0
  Mg  Mg3  1  0.664  0.336  0.500  1.0
  Mg  Mg4  1  0.106  0.894  0.000  1.0
  Mg  Mg5  1  0.447  0.553  0.000  1.0
[/CIF]
.