The structure 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 7-coordinate geometry to two equivalent Si(3) and five equivalent Si(1) atoms. In the second Mg site, Mg(2) is bonded in a 8-coordinate geometry to two equivalent Si(3) and six equivalent Si(2) atoms. In the third Mg site, Mg(3) is bonded in a 8-coordinate geometry to two equivalent Si(1), two equivalent Si(2), and four equivalent Si(3) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Mg(3), five equivalent Mg(1), and two equivalent Si(1) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Mg(3), six equivalent Mg(2), and one Si(3) atom. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), four equivalent Mg(3), and one Si(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.949
_cell_length_b   5.037
_cell_length_c   14.414
_cell_angle_alpha   87.501
_cell_angle_beta   85.510
_cell_angle_gamma   89.797
_symmetry_Int_Tables_number   1
_cell_volume   213.270
_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  0.200  0.074  0.595  1.0
  Mg  Mg1  1  0.037  0.782  0.927  1.0
  Mg  Mg2  1  0.870  0.487  0.260  1.0
  Mg  Mg3  1  0.130  0.513  0.740  1.0
  Mg  Mg4  1  0.963  0.218  0.073  1.0
  Mg  Mg5  1  0.800  0.926  0.405  1.0
  Si  Si6  1  0.700  0.590  0.568  1.0
  Si  Si7  1  0.554  0.291  0.901  1.0
  Si  Si8  1  0.379  0.995  0.232  1.0
  Si  Si9  1  0.621  0.005  0.768  1.0
  Si  Si10  1  0.446  0.709  0.099  1.0
  Si  Si11  1  0.300  0.410  0.432  1.0
[/CIF]
.
The structure 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 7-coordinate geometry to two equivalent Si(3) and five equivalent Si(1) atoms. In the second Mg site, Mg(2) is bonded in a 8-coordinate geometry to two equivalent Si(3) and six equivalent Si(2) atoms. In the third Mg site, Mg(3) is bonded in a 8-coordinate geometry to two equivalent Si(1), two equivalent Si(2), and four equivalent Si(3) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Mg(3), five equivalent Mg(1), and two equivalent Si(1) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Mg(3), six equivalent Mg(2), and one Si(3) atom. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), four equivalent Mg(3), and one Si(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.949
_cell_length_b   5.037
_cell_length_c   14.414
_cell_angle_alpha   87.501
_cell_angle_beta   85.510
_cell_angle_gamma   89.797
_symmetry_Int_Tables_number   1
_cell_volume   213.270
_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  0.200  0.074  0.595  1.0
  Mg  Mg1  1  0.037  0.782  0.927  1.0
  Mg  Mg2  1  0.870  0.487  0.260  1.0
  Mg  Mg3  1  0.130  0.513  0.740  1.0
  Mg  Mg4  1  0.963  0.218  0.073  1.0
  Mg  Mg5  1  0.800  0.926  0.405  1.0
  Si  Si6  1  0.700  0.590  0.568  1.0
  Si  Si7  1  0.554  0.291  0.901  1.0
  Si  Si8  1  0.379  0.995  0.232  1.0
  Si  Si9  1  0.621  0.005  0.768  1.0
  Si  Si10  1  0.446  0.709  0.099  1.0
  Si  Si11  1  0.300  0.410  0.432  1.0
[/CIF]
.