The material 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(2), one Si(3), and two equivalent Si(1) atoms. In the second Mg site, Mg(2) is bonded in a 3-coordinate geometry to one Si(1), one Si(2), and two equivalent Si(3) atoms. In the third Mg site, Mg(3) is bonded in a 7-coordinate geometry to one Si(1), three equivalent Si(2), and three equivalent Si(3) atoms. In the fourth Mg site, Mg(4) is bonded in a 7-coordinate geometry to one Si(3), three equivalent Si(1), and three 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), two equivalent Mg(1), three equivalent Mg(4), and one Si(1) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to one Mg(1), one Mg(2), three equivalent Mg(3), three equivalent Mg(4), and one Si(3) atom. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one Mg(1), one Mg(4), two equivalent Mg(2), three equivalent Mg(3), one Si(2), and one Si(3) atom. is represented by the CIF file [CIF]
data_Mg4Si3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.686
_cell_length_b   7.506
_cell_length_c   7.617
_cell_angle_alpha   85.651
_cell_angle_beta   81.560
_cell_angle_gamma   82.341
_symmetry_Int_Tables_number   1
_cell_volume   262.176
_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  0.052  0.026  0.294  1.0
  Mg  Mg1  1  0.543  0.793  0.533  1.0
  Mg  Mg2  1  0.316  0.452  0.770  1.0
  Mg  Mg3  1  0.812  0.260  0.977  1.0
  Mg  Mg4  1  0.188  0.740  0.023  1.0
  Mg  Mg5  1  0.457  0.207  0.467  1.0
  Mg  Mg6  1  0.684  0.548  0.230  1.0
  Mg  Mg7  1  0.948  0.974  0.706  1.0
  Si  Si8  1  0.386  0.075  0.871  1.0
  Si  Si9  1  0.614  0.925  0.129  1.0
  Si  Si10  1  0.763  0.630  0.833  1.0
  Si  Si11  1  0.884  0.375  0.578  1.0
  Si  Si12  1  0.116  0.625  0.422  1.0
  Si  Si13  1  0.237  0.370  0.167  1.0
[/CIF]
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The material 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(2), one Si(3), and two equivalent Si(1) atoms. In the second Mg site, Mg(2) is bonded in a 3-coordinate geometry to one Si(1), one Si(2), and two equivalent Si(3) atoms. In the third Mg site, Mg(3) is bonded in a 7-coordinate geometry to one Si(1), three equivalent Si(2), and three equivalent Si(3) atoms. In the fourth Mg site, Mg(4) is bonded in a 7-coordinate geometry to one Si(3), three equivalent Si(1), and three 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), two equivalent Mg(1), three equivalent Mg(4), and one Si(1) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to one Mg(1), one Mg(2), three equivalent Mg(3), three equivalent Mg(4), and one Si(3) atom. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one Mg(1), one Mg(4), two equivalent Mg(2), three equivalent Mg(3), one Si(2), and one Si(3) atom. is represented by the CIF file [CIF]
data_Mg4Si3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.686
_cell_length_b   7.506
_cell_length_c   7.617
_cell_angle_alpha   85.651
_cell_angle_beta   81.560
_cell_angle_gamma   82.341
_symmetry_Int_Tables_number   1
_cell_volume   262.176
_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  0.052  0.026  0.294  1.0
  Mg  Mg1  1  0.543  0.793  0.533  1.0
  Mg  Mg2  1  0.316  0.452  0.770  1.0
  Mg  Mg3  1  0.812  0.260  0.977  1.0
  Mg  Mg4  1  0.188  0.740  0.023  1.0
  Mg  Mg5  1  0.457  0.207  0.467  1.0
  Mg  Mg6  1  0.684  0.548  0.230  1.0
  Mg  Mg7  1  0.948  0.974  0.706  1.0
  Si  Si8  1  0.386  0.075  0.871  1.0
  Si  Si9  1  0.614  0.925  0.129  1.0
  Si  Si10  1  0.763  0.630  0.833  1.0
  Si  Si11  1  0.884  0.375  0.578  1.0
  Si  Si12  1  0.116  0.625  0.422  1.0
  Si  Si13  1  0.237  0.370  0.167  1.0
[/CIF]
.