The material structure described by MgSi2 crystallizes in the trigonal R-3m space group. Mg(1) is bonded in a 7-coordinate geometry to three equivalent Si(1) and four equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to three equivalent Mg(1) and three equivalent Si(1) atoms to form distorted edge-sharing SiMg3Si3 octahedra. In the second Si site, Si(2) is bonded in a 7-coordinate geometry to four equivalent Mg(1) and three equivalent Si(2) atoms. is represented by the CIF card [CIF]
data_MgSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.742
_cell_length_b   9.742
_cell_length_c   9.742
_cell_angle_alpha   22.187
_cell_angle_beta   22.187
_cell_angle_gamma   22.187
_symmetry_Int_Tables_number   1
_cell_volume   115.622
_cell_formula_units_Z   2
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  0.918  0.918  0.918  1.0
  Mg  Mg1  1  0.082  0.082  0.082  1.0
  Si  Si2  1  0.351  0.351  0.351  1.0
  Si  Si3  1  0.185  0.185  0.185  1.0
  Si  Si4  1  0.649  0.649  0.649  1.0
  Si  Si5  1  0.815  0.815  0.815  1.0
[/CIF]
.
The material structure described by MgSi2 crystallizes in the trigonal R-3m space group. Mg(1) is bonded in a 7-coordinate geometry to three equivalent Si(1) and four equivalent Si(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to three equivalent Mg(1) and three equivalent Si(1) atoms to form distorted edge-sharing SiMg3Si3 octahedra. In the second Si site, Si(2) is bonded in a 7-coordinate geometry to four equivalent Mg(1) and three equivalent Si(2) atoms. is represented by the CIF card [CIF]
data_MgSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.742
_cell_length_b   9.742
_cell_length_c   9.742
_cell_angle_alpha   22.187
_cell_angle_beta   22.187
_cell_angle_gamma   22.187
_symmetry_Int_Tables_number   1
_cell_volume   115.622
_cell_formula_units_Z   2
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  0.918  0.918  0.918  1.0
  Mg  Mg1  1  0.082  0.082  0.082  1.0
  Si  Si2  1  0.351  0.351  0.351  1.0
  Si  Si3  1  0.185  0.185  0.185  1.0
  Si  Si4  1  0.649  0.649  0.649  1.0
  Si  Si5  1  0.815  0.815  0.815  1.0
[/CIF]
.