The material described by Mg2Si crystallizes in the triclinic P-1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 4-coordinate geometry to two equivalent Si(1) and two equivalent Si(2) atoms. In the second Mg site, Mg(2) is bonded in a 4-coordinate geometry to two equivalent Si(1) and two equivalent Si(2) atoms. In the third Mg site, Mg(3) is bonded in a 4-coordinate geometry to two equivalent Si(2) and three equivalent Si(1) atoms. In the fourth Mg site, Mg(4) is bonded in a 4-coordinate geometry to two equivalent Si(1) and two equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 10-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), three equivalent Mg(3), and one Si(2) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and one Si(1) atom. is represented by the CIF card [CIF]
data_Mg2Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.768
_cell_length_b   6.030
_cell_length_c   7.605
_cell_angle_alpha   87.179
_cell_angle_beta   110.997
_cell_angle_gamma   107.915
_symmetry_Int_Tables_number   1
_cell_volume   234.422
_cell_formula_units_Z   4
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  0.234  0.183  0.491  1.0
  Mg  Mg1  1  0.819  0.823  0.127  1.0
  Mg  Mg2  1  0.766  0.817  0.509  1.0
  Mg  Mg3  1  0.818  0.321  0.103  1.0
  Mg  Mg4  1  0.220  0.679  0.462  1.0
  Mg  Mg5  1  0.182  0.679  0.897  1.0
  Mg  Mg6  1  0.181  0.177  0.873  1.0
  Mg  Mg7  1  0.780  0.321  0.538  1.0
  Si  Si8  1  0.604  0.566  0.783  1.0
  Si  Si9  1  0.396  0.434  0.217  1.0
  Si  Si10  1  0.395  0.017  0.218  1.0
  Si  Si11  1  0.605  0.983  0.782  1.0
[/CIF]
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The material described by Mg2Si crystallizes in the triclinic P-1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 4-coordinate geometry to two equivalent Si(1) and two equivalent Si(2) atoms. In the second Mg site, Mg(2) is bonded in a 4-coordinate geometry to two equivalent Si(1) and two equivalent Si(2) atoms. In the third Mg site, Mg(3) is bonded in a 4-coordinate geometry to two equivalent Si(2) and three equivalent Si(1) atoms. In the fourth Mg site, Mg(4) is bonded in a 4-coordinate geometry to two equivalent Si(1) and two equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 10-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), three equivalent Mg(3), and one Si(2) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and one Si(1) atom. is represented by the CIF card [CIF]
data_Mg2Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.768
_cell_length_b   6.030
_cell_length_c   7.605
_cell_angle_alpha   87.179
_cell_angle_beta   110.997
_cell_angle_gamma   107.915
_symmetry_Int_Tables_number   1
_cell_volume   234.422
_cell_formula_units_Z   4
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  0.234  0.183  0.491  1.0
  Mg  Mg1  1  0.819  0.823  0.127  1.0
  Mg  Mg2  1  0.766  0.817  0.509  1.0
  Mg  Mg3  1  0.818  0.321  0.103  1.0
  Mg  Mg4  1  0.220  0.679  0.462  1.0
  Mg  Mg5  1  0.182  0.679  0.897  1.0
  Mg  Mg6  1  0.181  0.177  0.873  1.0
  Mg  Mg7  1  0.780  0.321  0.538  1.0
  Si  Si8  1  0.604  0.566  0.783  1.0
  Si  Si9  1  0.396  0.434  0.217  1.0
  Si  Si10  1  0.395  0.017  0.218  1.0
  Si  Si11  1  0.605  0.983  0.782  1.0
[/CIF]
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