The structure described by Mg4Si3 crystallizes in the monoclinic C2 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(4), two equivalent Si(1), and two equivalent Si(2) atoms. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to one Si(3), one Si(4), two equivalent Si(1), and two equivalent Si(2) atoms. In the third Mg site, Mg(3) is bonded in a 6-coordinate geometry to one Si(3), one Si(4), two equivalent Si(1), and two equivalent Si(2) atoms. In the fourth Mg site, Mg(4) is bonded in a 5-coordinate geometry to one Si(3), two equivalent Si(1), and two equivalent Si(2) atoms. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 8-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), and two equivalent Mg(4) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and one Si(3) atom. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), one Si(4), and two equivalent Si(2) atoms. In the fourth Si site, Si(4) is bonded in a 7-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), and one Si(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg4Si3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.661
_cell_length_b   7.661
_cell_length_c   7.344
_cell_angle_alpha   63.205
_cell_angle_beta   63.205
_cell_angle_gamma   44.281
_symmetry_Int_Tables_number   1
_cell_volume   262.916
_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  0.078  0.766  0.232  1.0
  Mg  Mg1  1  0.703  0.883  0.692  1.0
  Mg  Mg2  1  0.610  0.793  0.315  1.0
  Mg  Mg3  1  0.117  0.297  0.308  1.0
  Mg  Mg4  1  0.752  0.439  0.071  1.0
  Mg  Mg5  1  0.561  0.248  0.929  1.0
  Mg  Mg6  1  0.234  0.922  0.768  1.0
  Mg  Mg7  1  0.207  0.390  0.685  1.0
  Si  Si8  1  0.307  0.991  0.059  1.0
  Si  Si9  1  0.530  0.211  0.328  1.0
  Si  Si10  1  0.686  0.314  0.500  1.0
  Si  Si11  1  0.789  0.470  0.672  1.0
  Si  Si12  1  0.009  0.693  0.941  1.0
  Si  Si13  1  0.134  0.866  0.500  1.0
[/CIF]
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The structure described by Mg4Si3 crystallizes in the monoclinic C2 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(4), two equivalent Si(1), and two equivalent Si(2) atoms. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to one Si(3), one Si(4), two equivalent Si(1), and two equivalent Si(2) atoms. In the third Mg site, Mg(3) is bonded in a 6-coordinate geometry to one Si(3), one Si(4), two equivalent Si(1), and two equivalent Si(2) atoms. In the fourth Mg site, Mg(4) is bonded in a 5-coordinate geometry to one Si(3), two equivalent Si(1), and two equivalent Si(2) atoms. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 8-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), and two equivalent Mg(4) atoms. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and one Si(3) atom. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), one Si(4), and two equivalent Si(2) atoms. In the fourth Si site, Si(4) is bonded in a 7-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), and one Si(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg4Si3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.661
_cell_length_b   7.661
_cell_length_c   7.344
_cell_angle_alpha   63.205
_cell_angle_beta   63.205
_cell_angle_gamma   44.281
_symmetry_Int_Tables_number   1
_cell_volume   262.916
_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  0.078  0.766  0.232  1.0
  Mg  Mg1  1  0.703  0.883  0.692  1.0
  Mg  Mg2  1  0.610  0.793  0.315  1.0
  Mg  Mg3  1  0.117  0.297  0.308  1.0
  Mg  Mg4  1  0.752  0.439  0.071  1.0
  Mg  Mg5  1  0.561  0.248  0.929  1.0
  Mg  Mg6  1  0.234  0.922  0.768  1.0
  Mg  Mg7  1  0.207  0.390  0.685  1.0
  Si  Si8  1  0.307  0.991  0.059  1.0
  Si  Si9  1  0.530  0.211  0.328  1.0
  Si  Si10  1  0.686  0.314  0.500  1.0
  Si  Si11  1  0.789  0.470  0.672  1.0
  Si  Si12  1  0.009  0.693  0.941  1.0
  Si  Si13  1  0.134  0.866  0.500  1.0
[/CIF]
.