The crystal structure described by Mg6YSi 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 Si(1) atoms to form distorted MgY2Mg8Si2 cuboctahedra that share corners with four equivalent Mg(2)Y2Mg10 cuboctahedra, corners with four equivalent Y(1)Mg10Si2 cuboctahedra, corners with ten equivalent Mg(1)Y2Mg8Si2 cuboctahedra, edges with two equivalent Mg(2)Y2Mg10 cuboctahedra, edges with two equivalent Mg(1)Y2Mg8Si2 cuboctahedra, edges with two equivalent Y(1)Mg10Si2 cuboctahedra, edges with four equivalent Mg(4)Mg10Si2 cuboctahedra, faces with two equivalent Mg(4)Mg10Si2 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Mg10Si2 cuboctahedra, and faces with four equivalent Mg(1)Y2Mg8Si2 cuboctahedra. 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 Y(1) atoms to form MgY2Mg10 cuboctahedra that share corners with four equivalent Y(1)Mg10Si2 cuboctahedra, corners with six equivalent Mg(2)Y2Mg10 cuboctahedra, corners with eight equivalent Mg(1)Y2Mg8Si2 cuboctahedra, edges with two equivalent Y(1)Mg10Si2 cuboctahedra, edges with four equivalent Mg(4)Mg10Si2 cuboctahedra, edges with four equivalent Mg(1)Y2Mg8Si2 cuboctahedra, faces with two equivalent Mg(4)Mg10Si2 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Mg10Si2 cuboctahedra, and faces with four equivalent Mg(1)Y2Mg8Si2 cuboctahedra. In the third Mg site, Mg(3) 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 Y(1), and two equivalent Si(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 Si(1) atoms to form distorted MgMg10Si2 cuboctahedra that share corners with six equivalent Mg(4)Mg10Si2 cuboctahedra, edges with four equivalent Mg(2)Y2Mg10 cuboctahedra, edges with eight equivalent Mg(1)Y2Mg8Si2 cuboctahedra, faces with two equivalent Mg(4)Mg10Si2 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, faces with four equivalent Mg(1)Y2Mg8Si2 cuboctahedra, and faces with six equivalent Y(1)Mg10Si2 cuboctahedra. Y(1) is bonded to two equivalent Mg(2), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Si(1) atoms to form distorted YMg10Si2 cuboctahedra that share corners with four equivalent Mg(2)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)Mg10Si2 cuboctahedra, corners with eight equivalent Mg(1)Y2Mg8Si2 cuboctahedra, edges with two equivalent Mg(2)Y2Mg10 cuboctahedra, edges with four equivalent Mg(1)Y2Mg8Si2 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Mg10Si2 cuboctahedra, faces with four equivalent Mg(1)Y2Mg8Si2 cuboctahedra, and faces with six equivalent Mg(4)Mg10Si2 cuboctahedra. Si(1) is bonded in a 12-coordinate geometry to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Y(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_YMg6Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.950
_cell_length_b   6.473
_cell_length_c   6.473
_cell_angle_alpha   119.171
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   181.134
_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  0.000  0.666  0.827  1.0
  Mg  Mg1  1  0.000  0.173  0.334  1.0
  Mg  Mg2  1  0.000  0.665  0.335  1.0
  Mg  Mg3  1  0.500  0.817  0.659  1.0
  Mg  Mg4  1  0.500  0.341  0.183  1.0
  Mg  Mg5  1  0.500  0.832  0.168  1.0
  Si  Si6  1  0.500  0.328  0.672  1.0
  Y  Y7  1  0.000  0.178  0.822  1.0
[/CIF]
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The crystal structure described by Mg6YSi 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 Si(1) atoms to form distorted MgY2Mg8Si2 cuboctahedra that share corners with four equivalent Mg(2)Y2Mg10 cuboctahedra, corners with four equivalent Y(1)Mg10Si2 cuboctahedra, corners with ten equivalent Mg(1)Y2Mg8Si2 cuboctahedra, edges with two equivalent Mg(2)Y2Mg10 cuboctahedra, edges with two equivalent Mg(1)Y2Mg8Si2 cuboctahedra, edges with two equivalent Y(1)Mg10Si2 cuboctahedra, edges with four equivalent Mg(4)Mg10Si2 cuboctahedra, faces with two equivalent Mg(4)Mg10Si2 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Mg10Si2 cuboctahedra, and faces with four equivalent Mg(1)Y2Mg8Si2 cuboctahedra. 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 Y(1) atoms to form MgY2Mg10 cuboctahedra that share corners with four equivalent Y(1)Mg10Si2 cuboctahedra, corners with six equivalent Mg(2)Y2Mg10 cuboctahedra, corners with eight equivalent Mg(1)Y2Mg8Si2 cuboctahedra, edges with two equivalent Y(1)Mg10Si2 cuboctahedra, edges with four equivalent Mg(4)Mg10Si2 cuboctahedra, edges with four equivalent Mg(1)Y2Mg8Si2 cuboctahedra, faces with two equivalent Mg(4)Mg10Si2 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Mg10Si2 cuboctahedra, and faces with four equivalent Mg(1)Y2Mg8Si2 cuboctahedra. In the third Mg site, Mg(3) 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 Y(1), and two equivalent Si(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 Si(1) atoms to form distorted MgMg10Si2 cuboctahedra that share corners with six equivalent Mg(4)Mg10Si2 cuboctahedra, edges with four equivalent Mg(2)Y2Mg10 cuboctahedra, edges with eight equivalent Mg(1)Y2Mg8Si2 cuboctahedra, faces with two equivalent Mg(4)Mg10Si2 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, faces with four equivalent Mg(1)Y2Mg8Si2 cuboctahedra, and faces with six equivalent Y(1)Mg10Si2 cuboctahedra. Y(1) is bonded to two equivalent Mg(2), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Si(1) atoms to form distorted YMg10Si2 cuboctahedra that share corners with four equivalent Mg(2)Y2Mg10 cuboctahedra, corners with six equivalent Y(1)Mg10Si2 cuboctahedra, corners with eight equivalent Mg(1)Y2Mg8Si2 cuboctahedra, edges with two equivalent Mg(2)Y2Mg10 cuboctahedra, edges with four equivalent Mg(1)Y2Mg8Si2 cuboctahedra, faces with two equivalent Mg(2)Y2Mg10 cuboctahedra, faces with two equivalent Y(1)Mg10Si2 cuboctahedra, faces with four equivalent Mg(1)Y2Mg8Si2 cuboctahedra, and faces with six equivalent Mg(4)Mg10Si2 cuboctahedra. Si(1) is bonded in a 12-coordinate geometry to two equivalent Mg(4), four equivalent Mg(1), four equivalent Mg(3), and two equivalent Y(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_YMg6Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.950
_cell_length_b   6.473
_cell_length_c   6.473
_cell_angle_alpha   119.171
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   181.134
_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  0.000  0.666  0.827  1.0
  Mg  Mg1  1  0.000  0.173  0.334  1.0
  Mg  Mg2  1  0.000  0.665  0.335  1.0
  Mg  Mg3  1  0.500  0.817  0.659  1.0
  Mg  Mg4  1  0.500  0.341  0.183  1.0
  Mg  Mg5  1  0.500  0.832  0.168  1.0
  Si  Si6  1  0.500  0.328  0.672  1.0
  Y  Y7  1  0.000  0.178  0.822  1.0
[/CIF]
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