The material described by MgSi crystallizes in the monoclinic C2/m space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 5-coordinate geometry to three equivalent Si(3) and four equivalent Si(1) atoms. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to one Si(1), two equivalent Si(3), and three equivalent Si(2) atoms. In the third Mg site, Mg(3) is bonded in a 4-coordinate geometry to two equivalent Si(1), two equivalent Si(3), and four equivalent Si(2) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Mg(2), two equivalent Mg(3), four equivalent Mg(1), one Si(1), and one Si(3) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to three equivalent Mg(2), four equivalent Mg(3), one Si(2), and one Si(3) atom. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Mg(2), two equivalent Mg(3), three equivalent Mg(1), one Si(1), and one Si(2) atom. is represented by the CIF file [CIF]
data_MgSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.423
_cell_length_b   6.423
_cell_length_c   9.006
_cell_angle_alpha   76.365
_cell_angle_beta   76.365
_cell_angle_gamma   38.976
_symmetry_Int_Tables_number   1
_cell_volume   226.281
_cell_formula_units_Z   6
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  0.356  0.356  0.508  1.0
  Mg  Mg1  1  0.252  0.252  0.166  1.0
  Mg  Mg2  1  0.470  0.470  0.832  1.0
  Mg  Mg3  1  0.748  0.748  0.834  1.0
  Mg  Mg4  1  0.530  0.530  0.168  1.0
  Mg  Mg5  1  0.644  0.644  0.492  1.0
  Si  Si6  1  0.959  0.959  0.635  1.0
  Si  Si7  1  0.895  0.895  0.028  1.0
  Si  Si8  1  0.041  0.041  0.365  1.0
  Si  Si9  1  0.856  0.856  0.302  1.0
  Si  Si10  1  0.144  0.144  0.698  1.0
  Si  Si11  1  0.105  0.105  0.972  1.0
[/CIF]
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The material described by MgSi crystallizes in the monoclinic C2/m space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 5-coordinate geometry to three equivalent Si(3) and four equivalent Si(1) atoms. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to one Si(1), two equivalent Si(3), and three equivalent Si(2) atoms. In the third Mg site, Mg(3) is bonded in a 4-coordinate geometry to two equivalent Si(1), two equivalent Si(3), and four equivalent Si(2) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Mg(2), two equivalent Mg(3), four equivalent Mg(1), one Si(1), and one Si(3) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to three equivalent Mg(2), four equivalent Mg(3), one Si(2), and one Si(3) atom. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Mg(2), two equivalent Mg(3), three equivalent Mg(1), one Si(1), and one Si(2) atom. is represented by the CIF file [CIF]
data_MgSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.423
_cell_length_b   6.423
_cell_length_c   9.006
_cell_angle_alpha   76.365
_cell_angle_beta   76.365
_cell_angle_gamma   38.976
_symmetry_Int_Tables_number   1
_cell_volume   226.281
_cell_formula_units_Z   6
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  0.356  0.356  0.508  1.0
  Mg  Mg1  1  0.252  0.252  0.166  1.0
  Mg  Mg2  1  0.470  0.470  0.832  1.0
  Mg  Mg3  1  0.748  0.748  0.834  1.0
  Mg  Mg4  1  0.530  0.530  0.168  1.0
  Mg  Mg5  1  0.644  0.644  0.492  1.0
  Si  Si6  1  0.959  0.959  0.635  1.0
  Si  Si7  1  0.895  0.895  0.028  1.0
  Si  Si8  1  0.041  0.041  0.365  1.0
  Si  Si9  1  0.856  0.856  0.302  1.0
  Si  Si10  1  0.144  0.144  0.698  1.0
  Si  Si11  1  0.105  0.105  0.972  1.0
[/CIF]
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