The crystal structure described by MgSi crystallizes in the monoclinic C2/m space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 7-coordinate geometry to four equivalent Si(1) and five equivalent Si(3) atoms. In the second Mg site, Mg(2) is bonded to one Si(1), one Si(3), and two equivalent Si(2) atoms to form distorted corner-sharing MgSi4 trigonal pyramids. In the third Mg site, Mg(3) is bonded in a 5-coordinate geometry to one Si(1) and four equivalent Si(2) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 8-coordinate geometry to one Mg(2), one Mg(3), four equivalent Mg(1), and two equivalent Si(3) atoms. In the second Si site, Si(2) is bonded in a 7-coordinate geometry to two equivalent Mg(2), four equivalent Mg(3), and one Si(2) atom. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one Mg(2), five equivalent Mg(1), one Si(3), and two equivalent Si(1) atoms. is represented by the CIF card [CIF]
data_MgSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.078
_cell_length_b   5.078
_cell_length_c   11.844
_cell_angle_alpha   79.332
_cell_angle_beta   79.332
_cell_angle_gamma   51.873
_symmetry_Int_Tables_number   1
_cell_volume   235.112
_cell_formula_units_Z   6
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  0.872  0.872  0.415  1.0
  Mg  Mg1  1  0.520  0.520  0.792  1.0
  Mg  Mg2  1  0.223  0.223  0.097  1.0
  Mg  Mg3  1  0.480  0.480  0.208  1.0
  Mg  Mg4  1  0.777  0.777  0.903  1.0
  Mg  Mg5  1  0.128  0.128  0.585  1.0
  Si  Si6  1  0.182  0.182  0.340  1.0
  Si  Si7  1  0.092  0.092  0.905  1.0
  Si  Si8  1  0.818  0.818  0.660  1.0
  Si  Si9  1  0.423  0.423  0.592  1.0
  Si  Si10  1  0.577  0.577  0.408  1.0
  Si  Si11  1  0.908  0.908  0.095  1.0
[/CIF]
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The crystal structure described by MgSi crystallizes in the monoclinic C2/m space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 7-coordinate geometry to four equivalent Si(1) and five equivalent Si(3) atoms. In the second Mg site, Mg(2) is bonded to one Si(1), one Si(3), and two equivalent Si(2) atoms to form distorted corner-sharing MgSi4 trigonal pyramids. In the third Mg site, Mg(3) is bonded in a 5-coordinate geometry to one Si(1) and four equivalent Si(2) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 8-coordinate geometry to one Mg(2), one Mg(3), four equivalent Mg(1), and two equivalent Si(3) atoms. In the second Si site, Si(2) is bonded in a 7-coordinate geometry to two equivalent Mg(2), four equivalent Mg(3), and one Si(2) atom. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one Mg(2), five equivalent Mg(1), one Si(3), and two equivalent Si(1) atoms. is represented by the CIF card [CIF]
data_MgSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.078
_cell_length_b   5.078
_cell_length_c   11.844
_cell_angle_alpha   79.332
_cell_angle_beta   79.332
_cell_angle_gamma   51.873
_symmetry_Int_Tables_number   1
_cell_volume   235.112
_cell_formula_units_Z   6
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  0.872  0.872  0.415  1.0
  Mg  Mg1  1  0.520  0.520  0.792  1.0
  Mg  Mg2  1  0.223  0.223  0.097  1.0
  Mg  Mg3  1  0.480  0.480  0.208  1.0
  Mg  Mg4  1  0.777  0.777  0.903  1.0
  Mg  Mg5  1  0.128  0.128  0.585  1.0
  Si  Si6  1  0.182  0.182  0.340  1.0
  Si  Si7  1  0.092  0.092  0.905  1.0
  Si  Si8  1  0.818  0.818  0.660  1.0
  Si  Si9  1  0.423  0.423  0.592  1.0
  Si  Si10  1  0.577  0.577  0.408  1.0
  Si  Si11  1  0.908  0.908  0.095  1.0
[/CIF]
.