The material described by MgSi crystallizes in the triclinic P-1 space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 13-coordinate geometry to one Mg(1), one Mg(2), two equivalent Mg(3), one Si(2), four equivalent Si(1), and four equivalent Si(3) atoms. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to one Mg(1), one Si(3), two equivalent Si(1), and three equivalent Si(2) atoms. In the third Mg site, Mg(3) is bonded to two equivalent Mg(1), one Si(1), and three equivalent Si(2) atoms to form distorted edge-sharing MgMg2Si4 tetrahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 10-coordinate geometry to one Mg(3), two equivalent Mg(2), four equivalent Mg(1), and three equivalent Si(3) atoms. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to one Mg(1), three equivalent Mg(2), three 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), four equivalent Mg(1), one Si(3), and three equivalent Si(1) atoms. is represented by the CIF file [CIF]
data_MgSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.429
_cell_length_b   5.539
_cell_length_c   9.863
_cell_angle_alpha   99.772
_cell_angle_beta   93.903
_cell_angle_gamma   110.035
_symmetry_Int_Tables_number   1
_cell_volume   221.913
_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  0.623  0.202  0.144  1.0
  Mg  Mg1  1  0.056  0.191  0.670  1.0
  Mg  Mg2  1  0.237  0.411  0.378  1.0
  Mg  Mg3  1  0.944  0.809  0.330  1.0
  Mg  Mg4  1  0.763  0.589  0.622  1.0
  Mg  Mg5  1  0.377  0.798  0.856  1.0
  Si  Si6  1  0.314  0.598  0.137  1.0
  Si  Si7  1  0.377  0.858  0.578  1.0
  Si  Si8  1  0.686  0.402  0.863  1.0
  Si  Si9  1  0.107  0.207  0.952  1.0
  Si  Si10  1  0.893  0.793  0.048  1.0
  Si  Si11  1  0.623  0.142  0.422  1.0
[/CIF]
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The material described by MgSi crystallizes in the triclinic P-1 space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 13-coordinate geometry to one Mg(1), one Mg(2), two equivalent Mg(3), one Si(2), four equivalent Si(1), and four equivalent Si(3) atoms. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to one Mg(1), one Si(3), two equivalent Si(1), and three equivalent Si(2) atoms. In the third Mg site, Mg(3) is bonded to two equivalent Mg(1), one Si(1), and three equivalent Si(2) atoms to form distorted edge-sharing MgMg2Si4 tetrahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 10-coordinate geometry to one Mg(3), two equivalent Mg(2), four equivalent Mg(1), and three equivalent Si(3) atoms. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to one Mg(1), three equivalent Mg(2), three 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), four equivalent Mg(1), one Si(3), and three equivalent Si(1) atoms. is represented by the CIF file [CIF]
data_MgSi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.429
_cell_length_b   5.539
_cell_length_c   9.863
_cell_angle_alpha   99.772
_cell_angle_beta   93.903
_cell_angle_gamma   110.035
_symmetry_Int_Tables_number   1
_cell_volume   221.913
_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  0.623  0.202  0.144  1.0
  Mg  Mg1  1  0.056  0.191  0.670  1.0
  Mg  Mg2  1  0.237  0.411  0.378  1.0
  Mg  Mg3  1  0.944  0.809  0.330  1.0
  Mg  Mg4  1  0.763  0.589  0.622  1.0
  Mg  Mg5  1  0.377  0.798  0.856  1.0
  Si  Si6  1  0.314  0.598  0.137  1.0
  Si  Si7  1  0.377  0.858  0.578  1.0
  Si  Si8  1  0.686  0.402  0.863  1.0
  Si  Si9  1  0.107  0.207  0.952  1.0
  Si  Si10  1  0.893  0.793  0.048  1.0
  Si  Si11  1  0.623  0.142  0.422  1.0
[/CIF]
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