The structure described by Mg4Si3 crystallizes in the triclinic P-1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 4-coordinate geometry to one Si(1), one Si(3), and two equivalent Si(2) atoms. In the second Mg site, Mg(2) is bonded in a 5-coordinate geometry to one Si(3), two equivalent Si(1), and two equivalent Si(2) atoms. In the third Mg site, Mg(3) is bonded in a 5-coordinate geometry to one Si(2), two equivalent Si(1), and two equivalent Si(3) atoms. In the fourth Mg site, Mg(4) is bonded in a 5-coordinate geometry to one Si(1), two equivalent Si(2), and two equivalent Si(3) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 7-coordinate geometry to one Mg(1), one Mg(4), two equivalent Mg(2), two equivalent Mg(3), and one Si(3) atom. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to one Mg(3), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), and one Si(2) atom. In the third Si site, Si(3) is bonded in a 7-coordinate geometry to one Mg(1), one Mg(2), two equivalent Mg(3), two equivalent Mg(4), and one Si(1) atom. is represented by the CIF card [CIF]
data_Mg4Si3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.108
_cell_length_b   6.320
_cell_length_c   8.363
_cell_angle_alpha   72.011
_cell_angle_beta   71.248
_cell_angle_gamma   75.783
_symmetry_Int_Tables_number   1
_cell_volume   286.866
_cell_formula_units_Z   2
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  0.882  0.405  0.201  1.0
  Mg  Mg1  1  0.277  0.012  0.952  1.0
  Mg  Mg2  1  0.299  0.053  0.386  1.0
  Mg  Mg3  1  0.701  0.947  0.614  1.0
  Mg  Mg4  1  0.118  0.595  0.799  1.0
  Mg  Mg5  1  0.317  0.601  0.298  1.0
  Mg  Mg6  1  0.683  0.399  0.702  1.0
  Mg  Mg7  1  0.723  0.988  0.048  1.0
  Si  Si8  1  0.966  0.953  0.274  1.0
  Si  Si9  1  0.367  0.363  0.055  1.0
  Si  Si10  1  0.034  0.047  0.726  1.0
  Si  Si11  1  0.676  0.709  0.396  1.0
  Si  Si12  1  0.633  0.637  0.945  1.0
  Si  Si13  1  0.324  0.291  0.604  1.0
[/CIF]
.
The structure described by Mg4Si3 crystallizes in the triclinic P-1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 4-coordinate geometry to one Si(1), one Si(3), and two equivalent Si(2) atoms. In the second Mg site, Mg(2) is bonded in a 5-coordinate geometry to one Si(3), two equivalent Si(1), and two equivalent Si(2) atoms. In the third Mg site, Mg(3) is bonded in a 5-coordinate geometry to one Si(2), two equivalent Si(1), and two equivalent Si(3) atoms. In the fourth Mg site, Mg(4) is bonded in a 5-coordinate geometry to one Si(1), two equivalent Si(2), and two equivalent Si(3) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 7-coordinate geometry to one Mg(1), one Mg(4), two equivalent Mg(2), two equivalent Mg(3), and one Si(3) atom. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to one Mg(3), two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), and one Si(2) atom. In the third Si site, Si(3) is bonded in a 7-coordinate geometry to one Mg(1), one Mg(2), two equivalent Mg(3), two equivalent Mg(4), and one Si(1) atom. is represented by the CIF card [CIF]
data_Mg4Si3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.108
_cell_length_b   6.320
_cell_length_c   8.363
_cell_angle_alpha   72.011
_cell_angle_beta   71.248
_cell_angle_gamma   75.783
_symmetry_Int_Tables_number   1
_cell_volume   286.866
_cell_formula_units_Z   2
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  0.882  0.405  0.201  1.0
  Mg  Mg1  1  0.277  0.012  0.952  1.0
  Mg  Mg2  1  0.299  0.053  0.386  1.0
  Mg  Mg3  1  0.701  0.947  0.614  1.0
  Mg  Mg4  1  0.118  0.595  0.799  1.0
  Mg  Mg5  1  0.317  0.601  0.298  1.0
  Mg  Mg6  1  0.683  0.399  0.702  1.0
  Mg  Mg7  1  0.723  0.988  0.048  1.0
  Si  Si8  1  0.966  0.953  0.274  1.0
  Si  Si9  1  0.367  0.363  0.055  1.0
  Si  Si10  1  0.034  0.047  0.726  1.0
  Si  Si11  1  0.676  0.709  0.396  1.0
  Si  Si12  1  0.633  0.637  0.945  1.0
  Si  Si13  1  0.324  0.291  0.604  1.0
[/CIF]
.