The material structure described by MgSi2 crystallizes in the triclinic P-1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 10-coordinate geometry to two equivalent Si(1), two equivalent Si(2), three equivalent Si(3), and three equivalent Si(4) atoms. In the second Mg site, Mg(2) is bonded in a 10-coordinate geometry to two equivalent Si(3), two equivalent Si(4), three equivalent Si(1), and three equivalent Si(2) atoms. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Mg(1), three equivalent Mg(2), two equivalent Si(1), and two equivalent Si(3) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Mg(1), three equivalent Mg(2), two equivalent Si(2), and two equivalent Si(4) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Mg(2), three equivalent Mg(1), two equivalent Si(1), and two equivalent Si(3) atoms. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to two equivalent Mg(2), three equivalent Mg(1), two equivalent Si(2), and two equivalent Si(4) atoms. is represented by the CIF card [CIF]
data_MgSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.181
_cell_length_b   3.430
_cell_length_c   5.251
_cell_angle_alpha   106.766
_cell_angle_beta   107.426
_cell_angle_gamma   92.189
_symmetry_Int_Tables_number   1
_cell_volume   51.848
_cell_formula_units_Z   1
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  0.917  0.251  1.000  1.0
  Si  Si1  1  0.219  0.550  0.605  1.0
  Si  Si2  1  0.614  0.953  0.395  1.0
[/CIF]
.
The material structure described by MgSi2 crystallizes in the triclinic P-1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 10-coordinate geometry to two equivalent Si(1), two equivalent Si(2), three equivalent Si(3), and three equivalent Si(4) atoms. In the second Mg site, Mg(2) is bonded in a 10-coordinate geometry to two equivalent Si(3), two equivalent Si(4), three equivalent Si(1), and three equivalent Si(2) atoms. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Mg(1), three equivalent Mg(2), two equivalent Si(1), and two equivalent Si(3) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Mg(1), three equivalent Mg(2), two equivalent Si(2), and two equivalent Si(4) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Mg(2), three equivalent Mg(1), two equivalent Si(1), and two equivalent Si(3) atoms. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to two equivalent Mg(2), three equivalent Mg(1), two equivalent Si(2), and two equivalent Si(4) atoms. is represented by the CIF card [CIF]
data_MgSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.181
_cell_length_b   3.430
_cell_length_c   5.251
_cell_angle_alpha   106.766
_cell_angle_beta   107.426
_cell_angle_gamma   92.189
_symmetry_Int_Tables_number   1
_cell_volume   51.848
_cell_formula_units_Z   1
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  0.917  0.251  1.000  1.0
  Si  Si1  1  0.219  0.550  0.605  1.0
  Si  Si2  1  0.614  0.953  0.395  1.0
[/CIF]
.