The crystal structure described by Mg2Si crystallizes in the triclinic P-1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(2), six equivalent Mg(1), and four equivalent Si(1) atoms to form distorted MgMg8Si4 cuboctahedra that share corners with six equivalent Mg(2)Mg6Si6 cuboctahedra, corners with six equivalent Mg(1)Mg8Si4 cuboctahedra, edges with four equivalent Mg(1)Mg8Si4 cuboctahedra, edges with eleven equivalent Mg(2)Mg6Si6 cuboctahedra, faces with four equivalent Mg(2)Mg6Si6 cuboctahedra, and faces with eight equivalent Mg(1)Mg8Si4 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1), four equivalent Mg(2), and six equivalent Si(1) atoms to form distorted MgMg6Si6 cuboctahedra that share corners with six equivalent Mg(2)Mg6Si6 cuboctahedra, corners with six equivalent Mg(1)Mg8Si4 cuboctahedra, edges with eleven equivalent Mg(1)Mg8Si4 cuboctahedra, faces with four equivalent Mg(1)Mg8Si4 cuboctahedra, and faces with ten equivalent Mg(2)Mg6Si6 cuboctahedra. Si(1) is bonded in a 9-coordinate geometry to four equivalent Mg(1) and six equivalent Mg(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg2Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.978
_cell_length_b   5.036
_cell_length_c   7.743
_cell_angle_alpha   92.623
_cell_angle_beta   100.951
_cell_angle_gamma   90.003
_symmetry_Int_Tables_number   1
_cell_volume   113.865
_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
  Mg  Mg0  1  0.769  0.752  0.540  1.0
  Mg  Mg1  1  0.565  0.255  0.114  1.0
  Mg  Mg2  1  0.231  0.248  0.460  1.0
  Mg  Mg3  1  0.435  0.745  0.886  1.0
  Si  Si4  1  0.884  0.243  0.777  1.0
  Si  Si5  1  0.116  0.757  0.223  1.0
[/CIF]
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The crystal structure described by Mg2Si crystallizes in the triclinic P-1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(2), six equivalent Mg(1), and four equivalent Si(1) atoms to form distorted MgMg8Si4 cuboctahedra that share corners with six equivalent Mg(2)Mg6Si6 cuboctahedra, corners with six equivalent Mg(1)Mg8Si4 cuboctahedra, edges with four equivalent Mg(1)Mg8Si4 cuboctahedra, edges with eleven equivalent Mg(2)Mg6Si6 cuboctahedra, faces with four equivalent Mg(2)Mg6Si6 cuboctahedra, and faces with eight equivalent Mg(1)Mg8Si4 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1), four equivalent Mg(2), and six equivalent Si(1) atoms to form distorted MgMg6Si6 cuboctahedra that share corners with six equivalent Mg(2)Mg6Si6 cuboctahedra, corners with six equivalent Mg(1)Mg8Si4 cuboctahedra, edges with eleven equivalent Mg(1)Mg8Si4 cuboctahedra, faces with four equivalent Mg(1)Mg8Si4 cuboctahedra, and faces with ten equivalent Mg(2)Mg6Si6 cuboctahedra. Si(1) is bonded in a 9-coordinate geometry to four equivalent Mg(1) and six equivalent Mg(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg2Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.978
_cell_length_b   5.036
_cell_length_c   7.743
_cell_angle_alpha   92.623
_cell_angle_beta   100.951
_cell_angle_gamma   90.003
_symmetry_Int_Tables_number   1
_cell_volume   113.865
_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
  Mg  Mg0  1  0.769  0.752  0.540  1.0
  Mg  Mg1  1  0.565  0.255  0.114  1.0
  Mg  Mg2  1  0.231  0.248  0.460  1.0
  Mg  Mg3  1  0.435  0.745  0.886  1.0
  Si  Si4  1  0.884  0.243  0.777  1.0
  Si  Si5  1  0.116  0.757  0.223  1.0
[/CIF]
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