The material described by MgSi2 is Magnesium tetraboride-like structured and crystallizes in the monoclinic Cm space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 3-coordinate geometry to one Si(3), one Si(6), 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 one Mg(3), two equivalent Si(1), two equivalent Si(5), two equivalent Si(6), and two equivalent Si(7) atoms. In the third Mg site, Mg(3) is bonded in a 10-coordinate geometry to one Mg(2), two equivalent Mg(4), one Si(8), three equivalent Si(4), and three equivalent Si(7) atoms. In the fourth Mg site, Mg(4) is bonded in a 8-coordinate geometry to two equivalent Mg(3), one Si(2), one Si(4), three equivalent Si(3), and three equivalent Si(8) atoms. There are eight inequivalent Si sites. In the first Si site, Si(1) is bonded in a 6-coordinate geometry to two equivalent Mg(2), one Si(5), one Si(7), and two equivalent Si(6) atoms. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to one Mg(4), three equivalent Mg(1), two equivalent Si(3), and two equivalent Si(5) atoms. In the third Si site, Si(3) is bonded in a 8-coordinate geometry to one Mg(1), three equivalent Mg(4), two equivalent Si(2), and two equivalent Si(8) atoms. In the fourth Si site, Si(4) is bonded in a 7-coordinate geometry to one Mg(4), three equivalent Mg(3), one Si(8), and two equivalent Si(7) atoms. In the fifth Si site, Si(5) is bonded in a 9-coordinate geometry to two equivalent Mg(2), three equivalent Mg(1), one Si(1), one Si(6), and two equivalent Si(2) atoms. In the sixth Si site, Si(6) is bonded in a 6-coordinate geometry to one Mg(1), two equivalent Mg(2), one Si(5), and two equivalent Si(1) atoms. In the seventh Si site, Si(7) is bonded in a 7-coordinate geometry to two equivalent Mg(2), three equivalent Mg(3), one Si(1), and two equivalent Si(4) atoms. In the eighth Si site, Si(8) is bonded in a 7-coordinate geometry to one Mg(3), three equivalent Mg(4), one Si(4), and two equivalent Si(3) atoms. is represented by the CIF card [CIF]
data_MgSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.481
_cell_length_b   5.481
_cell_length_c   12.161
_cell_angle_alpha   77.507
_cell_angle_beta   77.507
_cell_angle_gamma   40.027
_symmetry_Int_Tables_number   1
_cell_volume   228.683
_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  0.112  0.112  0.131  1.0
  Mg  Mg1  1  0.438  0.438  0.843  1.0
  Mg  Mg2  1  0.588  0.588  0.603  1.0
  Mg  Mg3  1  0.190  0.190  0.380  1.0
  Si  Si4  1  0.729  0.729  0.897  1.0
  Si  Si5  1  0.366  0.366  0.164  1.0
  Si  Si6  1  0.915  0.915  0.320  1.0
  Si  Si7  1  0.295  0.295  0.594  1.0
  Si  Si8  1  0.869  0.869  0.035  1.0
  Si  Si9  1  0.090  0.090  0.913  1.0
  Si  Si10  1  0.859  0.859  0.695  1.0
  Si  Si11  1  0.469  0.469  0.424  1.0
[/CIF]
.
The material described by MgSi2 is Magnesium tetraboride-like structured and crystallizes in the monoclinic Cm space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 3-coordinate geometry to one Si(3), one Si(6), 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 one Mg(3), two equivalent Si(1), two equivalent Si(5), two equivalent Si(6), and two equivalent Si(7) atoms. In the third Mg site, Mg(3) is bonded in a 10-coordinate geometry to one Mg(2), two equivalent Mg(4), one Si(8), three equivalent Si(4), and three equivalent Si(7) atoms. In the fourth Mg site, Mg(4) is bonded in a 8-coordinate geometry to two equivalent Mg(3), one Si(2), one Si(4), three equivalent Si(3), and three equivalent Si(8) atoms. There are eight inequivalent Si sites. In the first Si site, Si(1) is bonded in a 6-coordinate geometry to two equivalent Mg(2), one Si(5), one Si(7), and two equivalent Si(6) atoms. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to one Mg(4), three equivalent Mg(1), two equivalent Si(3), and two equivalent Si(5) atoms. In the third Si site, Si(3) is bonded in a 8-coordinate geometry to one Mg(1), three equivalent Mg(4), two equivalent Si(2), and two equivalent Si(8) atoms. In the fourth Si site, Si(4) is bonded in a 7-coordinate geometry to one Mg(4), three equivalent Mg(3), one Si(8), and two equivalent Si(7) atoms. In the fifth Si site, Si(5) is bonded in a 9-coordinate geometry to two equivalent Mg(2), three equivalent Mg(1), one Si(1), one Si(6), and two equivalent Si(2) atoms. In the sixth Si site, Si(6) is bonded in a 6-coordinate geometry to one Mg(1), two equivalent Mg(2), one Si(5), and two equivalent Si(1) atoms. In the seventh Si site, Si(7) is bonded in a 7-coordinate geometry to two equivalent Mg(2), three equivalent Mg(3), one Si(1), and two equivalent Si(4) atoms. In the eighth Si site, Si(8) is bonded in a 7-coordinate geometry to one Mg(3), three equivalent Mg(4), one Si(4), and two equivalent Si(3) atoms. is represented by the CIF card [CIF]
data_MgSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.481
_cell_length_b   5.481
_cell_length_c   12.161
_cell_angle_alpha   77.507
_cell_angle_beta   77.507
_cell_angle_gamma   40.027
_symmetry_Int_Tables_number   1
_cell_volume   228.683
_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  0.112  0.112  0.131  1.0
  Mg  Mg1  1  0.438  0.438  0.843  1.0
  Mg  Mg2  1  0.588  0.588  0.603  1.0
  Mg  Mg3  1  0.190  0.190  0.380  1.0
  Si  Si4  1  0.729  0.729  0.897  1.0
  Si  Si5  1  0.366  0.366  0.164  1.0
  Si  Si6  1  0.915  0.915  0.320  1.0
  Si  Si7  1  0.295  0.295  0.594  1.0
  Si  Si8  1  0.869  0.869  0.035  1.0
  Si  Si9  1  0.090  0.090  0.913  1.0
  Si  Si10  1  0.859  0.859  0.695  1.0
  Si  Si11  1  0.469  0.469  0.424  1.0
[/CIF]
.