The material structure described by MgSi2 is Magnesium tetraboride-like structured and crystallizes in the triclinic P1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 6-coordinate geometry to three equivalent Si(2) and three equivalent Si(5) atoms. In the second Mg site, Mg(2) is bonded in a 8-coordinate geometry to two equivalent Si(6), three equivalent Si(1), and three equivalent Si(5) atoms. In the third Mg site, Mg(3) is bonded in a 10-coordinate geometry to two equivalent Si(1), two equivalent Si(4), three equivalent Si(6), and three equivalent Si(7) atoms. In the fourth Mg site, Mg(4) is bonded in a 8-coordinate geometry to two equivalent Si(8), three equivalent Si(2), and three equivalent Si(3) atoms. There are eight inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Mg(3), three equivalent Mg(2), one Si(5), and three equivalent Si(6) atoms. In the second Si site, Si(2) is bonded in a 7-coordinate geometry to three equivalent Mg(1), three equivalent Mg(4), and one Si(3) atom. In the third Si site, Si(3) is bonded in a 8-coordinate geometry to three equivalent Mg(4), one Si(2), one Si(4), and three equivalent Si(8) atoms. In the fourth Si site, Si(4) is bonded in a 5-coordinate geometry to two equivalent Mg(3), one Si(3), and three equivalent Si(7) atoms. In the fifth Si site, Si(5) is bonded in a 7-coordinate geometry to three equivalent Mg(1), three equivalent Mg(2), and one Si(1) atom. In the sixth Si site, Si(6) is bonded in a 9-coordinate geometry to two equivalent Mg(2), three equivalent Mg(3), one Si(7), and three equivalent Si(1) atoms. In the seventh Si site, Si(7) is bonded in a 8-coordinate geometry to three equivalent Mg(3), one Si(6), one Si(8), and three equivalent Si(4) atoms. In the eighth Si site, Si(8) is bonded in a 5-coordinate geometry to two equivalent Mg(4), one Si(7), and three equivalent Si(3) atoms. is represented by the CIF file [CIF]
data_MgSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.794
_cell_length_b   4.656
_cell_length_c   13.154
_cell_angle_alpha   85.941
_cell_angle_beta   85.462
_cell_angle_gamma   67.338
_symmetry_Int_Tables_number   1
_cell_volume   213.533
_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  0.553  0.977  0.125  1.0
  Mg  Mg1  1  0.195  0.807  0.951  1.0
  Mg  Mg2  1  0.332  0.668  0.706  1.0
  Mg  Mg3  1  0.902  0.165  0.299  1.0
  Si  Si4  1  0.922  0.410  0.848  1.0
  Si  Si5  1  0.239  0.548  0.203  1.0
  Si  Si6  1  0.196  0.558  0.400  1.0
  Si  Si7  1  0.004  0.427  0.572  1.0
  Si  Si8  1  0.865  0.405  0.040  1.0
  Si  Si9  1  0.607  0.062  0.803  1.0
  Si  Si10  1  0.668  0.069  0.608  1.0
  Si  Si11  1  0.516  0.905  0.444  1.0
[/CIF]
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The material structure described by MgSi2 is Magnesium tetraboride-like structured and crystallizes in the triclinic P1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 6-coordinate geometry to three equivalent Si(2) and three equivalent Si(5) atoms. In the second Mg site, Mg(2) is bonded in a 8-coordinate geometry to two equivalent Si(6), three equivalent Si(1), and three equivalent Si(5) atoms. In the third Mg site, Mg(3) is bonded in a 10-coordinate geometry to two equivalent Si(1), two equivalent Si(4), three equivalent Si(6), and three equivalent Si(7) atoms. In the fourth Mg site, Mg(4) is bonded in a 8-coordinate geometry to two equivalent Si(8), three equivalent Si(2), and three equivalent Si(3) atoms. There are eight inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Mg(3), three equivalent Mg(2), one Si(5), and three equivalent Si(6) atoms. In the second Si site, Si(2) is bonded in a 7-coordinate geometry to three equivalent Mg(1), three equivalent Mg(4), and one Si(3) atom. In the third Si site, Si(3) is bonded in a 8-coordinate geometry to three equivalent Mg(4), one Si(2), one Si(4), and three equivalent Si(8) atoms. In the fourth Si site, Si(4) is bonded in a 5-coordinate geometry to two equivalent Mg(3), one Si(3), and three equivalent Si(7) atoms. In the fifth Si site, Si(5) is bonded in a 7-coordinate geometry to three equivalent Mg(1), three equivalent Mg(2), and one Si(1) atom. In the sixth Si site, Si(6) is bonded in a 9-coordinate geometry to two equivalent Mg(2), three equivalent Mg(3), one Si(7), and three equivalent Si(1) atoms. In the seventh Si site, Si(7) is bonded in a 8-coordinate geometry to three equivalent Mg(3), one Si(6), one Si(8), and three equivalent Si(4) atoms. In the eighth Si site, Si(8) is bonded in a 5-coordinate geometry to two equivalent Mg(4), one Si(7), and three equivalent Si(3) atoms. is represented by the CIF file [CIF]
data_MgSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.794
_cell_length_b   4.656
_cell_length_c   13.154
_cell_angle_alpha   85.941
_cell_angle_beta   85.462
_cell_angle_gamma   67.338
_symmetry_Int_Tables_number   1
_cell_volume   213.533
_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  0.553  0.977  0.125  1.0
  Mg  Mg1  1  0.195  0.807  0.951  1.0
  Mg  Mg2  1  0.332  0.668  0.706  1.0
  Mg  Mg3  1  0.902  0.165  0.299  1.0
  Si  Si4  1  0.922  0.410  0.848  1.0
  Si  Si5  1  0.239  0.548  0.203  1.0
  Si  Si6  1  0.196  0.558  0.400  1.0
  Si  Si7  1  0.004  0.427  0.572  1.0
  Si  Si8  1  0.865  0.405  0.040  1.0
  Si  Si9  1  0.607  0.062  0.803  1.0
  Si  Si10  1  0.668  0.069  0.608  1.0
  Si  Si11  1  0.516  0.905  0.444  1.0
[/CIF]
.