The compound 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 14-coordinate geometry to one Mg(1), one Mg(2), one Si(3), two equivalent Si(2), four equivalent Si(4), and five equivalent Si(1) atoms. In the second Mg site, Mg(2) is bonded in a 13-coordinate geometry to one Mg(1), two equivalent Mg(2), one Si(1), two equivalent Si(4), three equivalent Si(2), and four equivalent Si(3) atoms. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 10-coordinate geometry to one Mg(2), five equivalent Mg(1), one Si(1), one Si(2), and two equivalent Si(4) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Mg(1), three equivalent Mg(2), one Si(1), one Si(4), and two equivalent Si(3) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one Mg(1), four equivalent Mg(2), one Si(3), one Si(4), and two equivalent Si(2) atoms. In the fourth Si site, Si(4) is bonded in a 10-coordinate geometry to two equivalent Mg(2), four equivalent Mg(1), one Si(2), one Si(3), and two equivalent Si(1) atoms. is represented by the CIF card [CIF]
data_MgSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.540
_cell_length_b   5.126
_cell_length_c   9.625
_cell_angle_alpha   87.822
_cell_angle_beta   89.015
_cell_angle_gamma   65.275
_symmetry_Int_Tables_number   1
_cell_volume   203.317
_cell_formula_units_Z   4
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  0.097  0.298  0.889  1.0
  Mg  Mg1  1  0.903  0.702  0.111  1.0
  Mg  Mg2  1  0.750  0.997  0.391  1.0
  Mg  Mg3  1  0.250  0.003  0.609  1.0
  Si  Si4  1  0.607  0.296  0.091  1.0
  Si  Si5  1  0.393  0.704  0.909  1.0
  Si  Si6  1  0.534  0.418  0.698  1.0
  Si  Si7  1  0.064  0.377  0.377  1.0
  Si  Si8  1  0.782  0.937  0.826  1.0
  Si  Si9  1  0.218  0.063  0.174  1.0
  Si  Si10  1  0.466  0.582  0.302  1.0
  Si  Si11  1  0.936  0.623  0.623  1.0
[/CIF]
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The compound 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 14-coordinate geometry to one Mg(1), one Mg(2), one Si(3), two equivalent Si(2), four equivalent Si(4), and five equivalent Si(1) atoms. In the second Mg site, Mg(2) is bonded in a 13-coordinate geometry to one Mg(1), two equivalent Mg(2), one Si(1), two equivalent Si(4), three equivalent Si(2), and four equivalent Si(3) atoms. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 10-coordinate geometry to one Mg(2), five equivalent Mg(1), one Si(1), one Si(2), and two equivalent Si(4) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Mg(1), three equivalent Mg(2), one Si(1), one Si(4), and two equivalent Si(3) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one Mg(1), four equivalent Mg(2), one Si(3), one Si(4), and two equivalent Si(2) atoms. In the fourth Si site, Si(4) is bonded in a 10-coordinate geometry to two equivalent Mg(2), four equivalent Mg(1), one Si(2), one Si(3), and two equivalent Si(1) atoms. is represented by the CIF card [CIF]
data_MgSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.540
_cell_length_b   5.126
_cell_length_c   9.625
_cell_angle_alpha   87.822
_cell_angle_beta   89.015
_cell_angle_gamma   65.275
_symmetry_Int_Tables_number   1
_cell_volume   203.317
_cell_formula_units_Z   4
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  0.097  0.298  0.889  1.0
  Mg  Mg1  1  0.903  0.702  0.111  1.0
  Mg  Mg2  1  0.750  0.997  0.391  1.0
  Mg  Mg3  1  0.250  0.003  0.609  1.0
  Si  Si4  1  0.607  0.296  0.091  1.0
  Si  Si5  1  0.393  0.704  0.909  1.0
  Si  Si6  1  0.534  0.418  0.698  1.0
  Si  Si7  1  0.064  0.377  0.377  1.0
  Si  Si8  1  0.782  0.937  0.826  1.0
  Si  Si9  1  0.218  0.063  0.174  1.0
  Si  Si10  1  0.466  0.582  0.302  1.0
  Si  Si11  1  0.936  0.623  0.623  1.0
[/CIF]
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