The material structure described by MgSi2 crystallizes in the monoclinic P2/c space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 10-coordinate geometry to four equivalent Si(1) and six equivalent Si(2) atoms. In the second Mg site, Mg(2) is bonded in a 10-coordinate geometry to four equivalent Si(2) and six equivalent Si(1) atoms. There are two 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(2) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Mg(2), three equivalent Mg(1), two equivalent Si(1), and two equivalent Si(2) atoms. is represented by the CIF card [CIF]
data_MgSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.338
_cell_length_b   3.374
_cell_length_c   5.148
_cell_angle_alpha   108.963
_cell_angle_beta   108.089
_cell_angle_gamma   90.598
_symmetry_Int_Tables_number   1
_cell_volume   51.727
_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  0.251  0.083  1.000  1.0
  Si  Si1  1  0.550  0.384  0.601  1.0
  Si  Si2  1  0.952  0.783  0.399  1.0
[/CIF]
.
The material structure described by MgSi2 crystallizes in the monoclinic P2/c space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 10-coordinate geometry to four equivalent Si(1) and six equivalent Si(2) atoms. In the second Mg site, Mg(2) is bonded in a 10-coordinate geometry to four equivalent Si(2) and six equivalent Si(1) atoms. There are two 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(2) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Mg(2), three equivalent Mg(1), two equivalent Si(1), and two equivalent Si(2) atoms. is represented by the CIF card [CIF]
data_MgSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.338
_cell_length_b   3.374
_cell_length_c   5.148
_cell_angle_alpha   108.963
_cell_angle_beta   108.089
_cell_angle_gamma   90.598
_symmetry_Int_Tables_number   1
_cell_volume   51.727
_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  0.251  0.083  1.000  1.0
  Si  Si1  1  0.550  0.384  0.601  1.0
  Si  Si2  1  0.952  0.783  0.399  1.0
[/CIF]
.