The material described by Mg4Si3 crystallizes in the triclinic P1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 5-coordinate geometry to one Si(1), two equivalent Si(2), and two equivalent Si(3) atoms. In the second Mg site, Mg(2) is bonded in a 4-coordinate geometry to two equivalent Si(1) and two equivalent Si(2) atoms. In the third Mg site, Mg(3) is bonded in a 4-coordinate geometry to 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 6-coordinate geometry to one Mg(1), one Mg(4), two equivalent Mg(2), and two equivalent Mg(3) atoms. In the second Si site, Si(2) is bonded in a 7-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), and one Si(3) atom. In the third Si site, Si(3) is bonded in a 7-coordinate geometry to two equivalent Mg(1), two equivalent Mg(3), two equivalent Mg(4), and one Si(2) atom. is represented by the CIF file [CIF]
data_Mg4Si3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.419
_cell_length_b   5.562
_cell_length_c   6.473
_cell_angle_alpha   73.211
_cell_angle_beta   75.097
_cell_angle_gamma   79.960
_symmetry_Int_Tables_number   1
_cell_volume   146.322
_cell_formula_units_Z   1
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  0.320  0.334  0.937  1.0
  Mg  Mg1  1  0.504  0.234  0.448  1.0
  Mg  Mg2  1  0.675  0.810  0.192  1.0
  Mg  Mg3  1  0.857  0.697  0.707  1.0
  Si  Si4  1  0.088  0.020  0.325  1.0
  Si  Si5  1  0.934  0.193  0.715  1.0
  Si  Si6  1  0.247  0.837  0.926  1.0
[/CIF]
.
The material described by Mg4Si3 crystallizes in the triclinic P1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 5-coordinate geometry to one Si(1), two equivalent Si(2), and two equivalent Si(3) atoms. In the second Mg site, Mg(2) is bonded in a 4-coordinate geometry to two equivalent Si(1) and two equivalent Si(2) atoms. In the third Mg site, Mg(3) is bonded in a 4-coordinate geometry to 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 6-coordinate geometry to one Mg(1), one Mg(4), two equivalent Mg(2), and two equivalent Mg(3) atoms. In the second Si site, Si(2) is bonded in a 7-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(4), and one Si(3) atom. In the third Si site, Si(3) is bonded in a 7-coordinate geometry to two equivalent Mg(1), two equivalent Mg(3), two equivalent Mg(4), and one Si(2) atom. is represented by the CIF file [CIF]
data_Mg4Si3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.419
_cell_length_b   5.562
_cell_length_c   6.473
_cell_angle_alpha   73.211
_cell_angle_beta   75.097
_cell_angle_gamma   79.960
_symmetry_Int_Tables_number   1
_cell_volume   146.322
_cell_formula_units_Z   1
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  0.320  0.334  0.937  1.0
  Mg  Mg1  1  0.504  0.234  0.448  1.0
  Mg  Mg2  1  0.675  0.810  0.192  1.0
  Mg  Mg3  1  0.857  0.697  0.707  1.0
  Si  Si4  1  0.088  0.020  0.325  1.0
  Si  Si5  1  0.934  0.193  0.715  1.0
  Si  Si6  1  0.247  0.837  0.926  1.0
[/CIF]
.