The crystal structure described by MgY2 crystallizes in the hexagonal P-6m2 space group. Mg(1) is bonded in a 6-coordinate geometry to three equivalent Y(2) and three equivalent Y(3) atoms. There are three inequivalent Y sites. In the first Y site, Y(1) is bonded to six equivalent Y(1) and six equivalent Y(2) atoms to form YY12 cuboctahedra that share corners with six equivalent Y(1)Y12 cuboctahedra, edges with six equivalent Y(1)Y12 cuboctahedra, edges with twelve equivalent Y(2)Y9Mg3 cuboctahedra, faces with six equivalent Y(1)Y12 cuboctahedra, and faces with twelve equivalent Y(2)Y9Mg3 cuboctahedra. In the second Y site, Y(2) is bonded to three equivalent Mg(1), three equivalent Y(1), and six equivalent Y(2) atoms to form YY9Mg3 cuboctahedra that share corners with six equivalent Y(3)Y6Mg6 cuboctahedra, corners with twelve equivalent Y(2)Y9Mg3 cuboctahedra, edges with six equivalent Y(1)Y12 cuboctahedra, edges with six equivalent Y(2)Y9Mg3 cuboctahedra,  a faceface with one Y(3)Y6Mg6 cuboctahedra, faces with six equivalent Y(1)Y12 cuboctahedra, and faces with seven equivalent Y(2)Y9Mg3 cuboctahedra. In the third Y site, Y(3) is bonded to six equivalent Mg(1) and six equivalent Y(3) atoms to form YY6Mg6 cuboctahedra that share corners with six equivalent Y(3)Y6Mg6 cuboctahedra, corners with twelve equivalent Y(2)Y9Mg3 cuboctahedra, edges with six equivalent Y(3)Y6Mg6 cuboctahedra, faces with two equivalent Y(2)Y9Mg3 cuboctahedra, and faces with six equivalent Y(3)Y6Mg6 cuboctahedra. is represented by the CIF file [CIF]
data_Y2Mg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.550
_cell_length_b   3.550
_cell_length_c   16.712
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   182.445
_cell_formula_units_Z   2
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  0.000  0.000  0.500  1.0
  Y  Y1  1  0.667  0.333  0.329  1.0
  Y  Y2  1  0.667  0.333  0.000  1.0
  Y  Y3  1  0.667  0.333  0.671  1.0
  Mg  Mg4  1  0.000  0.000  0.165  1.0
  Mg  Mg5  1  0.000  0.000  0.835  1.0
[/CIF]
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The crystal structure described by MgY2 crystallizes in the hexagonal P-6m2 space group. Mg(1) is bonded in a 6-coordinate geometry to three equivalent Y(2) and three equivalent Y(3) atoms. There are three inequivalent Y sites. In the first Y site, Y(1) is bonded to six equivalent Y(1) and six equivalent Y(2) atoms to form YY12 cuboctahedra that share corners with six equivalent Y(1)Y12 cuboctahedra, edges with six equivalent Y(1)Y12 cuboctahedra, edges with twelve equivalent Y(2)Y9Mg3 cuboctahedra, faces with six equivalent Y(1)Y12 cuboctahedra, and faces with twelve equivalent Y(2)Y9Mg3 cuboctahedra. In the second Y site, Y(2) is bonded to three equivalent Mg(1), three equivalent Y(1), and six equivalent Y(2) atoms to form YY9Mg3 cuboctahedra that share corners with six equivalent Y(3)Y6Mg6 cuboctahedra, corners with twelve equivalent Y(2)Y9Mg3 cuboctahedra, edges with six equivalent Y(1)Y12 cuboctahedra, edges with six equivalent Y(2)Y9Mg3 cuboctahedra,  a faceface with one Y(3)Y6Mg6 cuboctahedra, faces with six equivalent Y(1)Y12 cuboctahedra, and faces with seven equivalent Y(2)Y9Mg3 cuboctahedra. In the third Y site, Y(3) is bonded to six equivalent Mg(1) and six equivalent Y(3) atoms to form YY6Mg6 cuboctahedra that share corners with six equivalent Y(3)Y6Mg6 cuboctahedra, corners with twelve equivalent Y(2)Y9Mg3 cuboctahedra, edges with six equivalent Y(3)Y6Mg6 cuboctahedra, faces with two equivalent Y(2)Y9Mg3 cuboctahedra, and faces with six equivalent Y(3)Y6Mg6 cuboctahedra. is represented by the CIF file [CIF]
data_Y2Mg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.550
_cell_length_b   3.550
_cell_length_c   16.712
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   182.445
_cell_formula_units_Z   2
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  0.000  0.000  0.500  1.0
  Y  Y1  1  0.667  0.333  0.329  1.0
  Y  Y2  1  0.667  0.333  0.000  1.0
  Y  Y3  1  0.667  0.333  0.671  1.0
  Mg  Mg4  1  0.000  0.000  0.165  1.0
  Mg  Mg5  1  0.000  0.000  0.835  1.0
[/CIF]
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