The material structure described by Mg4Si3 crystallizes in the trigonal R-3 space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 5-coordinate geometry to five equivalent Si(1) atoms. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to six equivalent Si(1) atoms. In the third Mg site, Mg(3) is bonded in an octahedral geometry to six equivalent Si(1) atoms. Si(1) is bonded in a 8-coordinate geometry to one Mg(2), one Mg(3), five equivalent Mg(1), and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg4Si3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.772
_cell_length_b   6.772
_cell_length_c   6.772
_cell_angle_alpha   105.741
_cell_angle_beta   105.741
_cell_angle_gamma   105.741
_symmetry_Int_Tables_number   1
_cell_volume   267.046
_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  0.843  0.254  0.386  1.0
  Mg  Mg1  1  0.254  0.386  0.843  1.0
  Mg  Mg2  1  0.500  0.500  0.500  1.0
  Mg  Mg3  1  0.386  0.843  0.254  1.0
  Mg  Mg4  1  0.746  0.614  0.157  1.0
  Mg  Mg5  1  0.000  0.000  0.000  1.0
  Mg  Mg6  1  0.614  0.157  0.746  1.0
  Mg  Mg7  1  0.157  0.746  0.614  1.0
  Si  Si8  1  0.451  0.164  0.077  1.0
  Si  Si9  1  0.164  0.077  0.451  1.0
  Si  Si10  1  0.836  0.923  0.549  1.0
  Si  Si11  1  0.549  0.836  0.923  1.0
  Si  Si12  1  0.077  0.451  0.164  1.0
  Si  Si13  1  0.923  0.549  0.836  1.0
[/CIF]
.
The material structure described by Mg4Si3 crystallizes in the trigonal R-3 space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 5-coordinate geometry to five equivalent Si(1) atoms. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to six equivalent Si(1) atoms. In the third Mg site, Mg(3) is bonded in an octahedral geometry to six equivalent Si(1) atoms. Si(1) is bonded in a 8-coordinate geometry to one Mg(2), one Mg(3), five equivalent Mg(1), and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg4Si3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.772
_cell_length_b   6.772
_cell_length_c   6.772
_cell_angle_alpha   105.741
_cell_angle_beta   105.741
_cell_angle_gamma   105.741
_symmetry_Int_Tables_number   1
_cell_volume   267.046
_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  0.843  0.254  0.386  1.0
  Mg  Mg1  1  0.254  0.386  0.843  1.0
  Mg  Mg2  1  0.500  0.500  0.500  1.0
  Mg  Mg3  1  0.386  0.843  0.254  1.0
  Mg  Mg4  1  0.746  0.614  0.157  1.0
  Mg  Mg5  1  0.000  0.000  0.000  1.0
  Mg  Mg6  1  0.614  0.157  0.746  1.0
  Mg  Mg7  1  0.157  0.746  0.614  1.0
  Si  Si8  1  0.451  0.164  0.077  1.0
  Si  Si9  1  0.164  0.077  0.451  1.0
  Si  Si10  1  0.836  0.923  0.549  1.0
  Si  Si11  1  0.549  0.836  0.923  1.0
  Si  Si12  1  0.077  0.451  0.164  1.0
  Si  Si13  1  0.923  0.549  0.836  1.0
[/CIF]
.