The compound described by MgSi crystallizes in the triclinic P-1 space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 5-coordinate geometry to one Si(1) and four equivalent Si(3) atoms. In the second Mg site, Mg(2) is bonded in a 8-coordinate geometry to one Si(3), three equivalent Si(2), and four equivalent Si(1) atoms. In the third Mg site, Mg(3) is bonded in a 4-coordinate geometry to one Si(2), two equivalent Si(1), and two equivalent Si(3) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 10-coordinate geometry to one Mg(1), two equivalent Mg(3), four equivalent Mg(2), and three equivalent Si(2) atoms. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to one Mg(3), three equivalent Mg(2), one Si(2), and three equivalent Si(1) atoms. In the third Si site, Si(3) is bonded in a 8-coordinate geometry to one Mg(2), two equivalent Mg(3), four equivalent Mg(1), and one Si(3) atom. is represented by the CIF file [CIF]
data_MgSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.791
_cell_length_b   4.495
_cell_length_c   10.379
_cell_angle_alpha   99.752
_cell_angle_beta   107.539
_cell_angle_gamma   61.324
_symmetry_Int_Tables_number   1
_cell_volume   225.913
_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  0.772  0.555  0.095  1.0
  Mg  Mg1  1  0.228  0.278  0.905  1.0
  Mg  Mg2  1  0.856  0.813  0.661  1.0
  Mg  Mg3  1  0.144  0.020  0.339  1.0
  Mg  Mg4  1  0.545  0.536  0.775  1.0
  Mg  Mg5  1  0.455  0.297  0.225  1.0
  Si  Si6  1  0.771  0.734  0.378  1.0
  Si  Si7  1  0.264  0.516  0.506  1.0
  Si  Si8  1  0.206  0.890  0.084  1.0
  Si  Si9  1  0.794  0.943  0.916  1.0
  Si  Si10  1  0.229  0.099  0.622  1.0
  Si  Si11  1  0.736  0.317  0.494  1.0
[/CIF]
.
The compound described by MgSi crystallizes in the triclinic P-1 space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 5-coordinate geometry to one Si(1) and four equivalent Si(3) atoms. In the second Mg site, Mg(2) is bonded in a 8-coordinate geometry to one Si(3), three equivalent Si(2), and four equivalent Si(1) atoms. In the third Mg site, Mg(3) is bonded in a 4-coordinate geometry to one Si(2), two equivalent Si(1), and two equivalent Si(3) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 10-coordinate geometry to one Mg(1), two equivalent Mg(3), four equivalent Mg(2), and three equivalent Si(2) atoms. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to one Mg(3), three equivalent Mg(2), one Si(2), and three equivalent Si(1) atoms. In the third Si site, Si(3) is bonded in a 8-coordinate geometry to one Mg(2), two equivalent Mg(3), four equivalent Mg(1), and one Si(3) atom. is represented by the CIF file [CIF]
data_MgSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.791
_cell_length_b   4.495
_cell_length_c   10.379
_cell_angle_alpha   99.752
_cell_angle_beta   107.539
_cell_angle_gamma   61.324
_symmetry_Int_Tables_number   1
_cell_volume   225.913
_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  0.772  0.555  0.095  1.0
  Mg  Mg1  1  0.228  0.278  0.905  1.0
  Mg  Mg2  1  0.856  0.813  0.661  1.0
  Mg  Mg3  1  0.144  0.020  0.339  1.0
  Mg  Mg4  1  0.545  0.536  0.775  1.0
  Mg  Mg5  1  0.455  0.297  0.225  1.0
  Si  Si6  1  0.771  0.734  0.378  1.0
  Si  Si7  1  0.264  0.516  0.506  1.0
  Si  Si8  1  0.206  0.890  0.084  1.0
  Si  Si9  1  0.794  0.943  0.916  1.0
  Si  Si10  1  0.229  0.099  0.622  1.0
  Si  Si11  1  0.736  0.317  0.494  1.0
[/CIF]
.