The crystal structure described by Mg3Si4 crystallizes in the triclinic P-1 space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 6-coordinate geometry to two equivalent Si(1), two equivalent Si(3), and two equivalent Si(4) atoms. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to one Si(1), two equivalent Si(2), two equivalent Si(3), and two equivalent Si(4) atoms. In the third Mg site, Mg(3) is bonded in a 7-coordinate geometry to one Si(1), one Si(3), two equivalent Si(2), and three equivalent Si(4) atoms. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 7-coordinate geometry to one Mg(2), one Mg(3), two equivalent Mg(1), one Si(1), one Si(2), and one Si(3) atom. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to two equivalent Mg(2), two equivalent Mg(3), one Si(1), one Si(3), and two equivalent Si(4) atoms. In the third Si site, Si(3) is bonded in a 8-coordinate geometry to one Mg(3), two equivalent Mg(1), two equivalent Mg(2), one Si(1), one Si(2), and one Si(4) atom. In the fourth Si site, Si(4) is bonded in a 10-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), three equivalent Mg(3), one Si(3), and two equivalent Si(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg3Si4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.445
_cell_length_b   6.978
_cell_length_c   7.864
_cell_angle_alpha   115.330
_cell_angle_beta   82.835
_cell_angle_gamma   110.727
_symmetry_Int_Tables_number   1
_cell_volume   252.475
_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  0.216  0.348  0.975  1.0
  Mg  Mg1  1  0.784  0.652  0.025  1.0
  Mg  Mg2  1  0.784  0.038  0.397  1.0
  Mg  Mg3  1  0.864  0.475  0.322  1.0
  Mg  Mg4  1  0.136  0.525  0.678  1.0
  Mg  Mg5  1  0.216  0.962  0.603  1.0
  Si  Si6  1  0.726  0.027  0.030  1.0
  Si  Si7  1  0.306  0.215  0.330  1.0
  Si  Si8  1  0.740  0.201  0.789  1.0
  Si  Si9  1  0.569  0.389  0.645  1.0
  Si  Si10  1  0.260  0.799  0.211  1.0
  Si  Si11  1  0.694  0.785  0.670  1.0
  Si  Si12  1  0.274  0.973  0.970  1.0
  Si  Si13  1  0.431  0.611  0.355  1.0
[/CIF]
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The crystal structure described by Mg3Si4 crystallizes in the triclinic P-1 space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 6-coordinate geometry to two equivalent Si(1), two equivalent Si(3), and two equivalent Si(4) atoms. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to one Si(1), two equivalent Si(2), two equivalent Si(3), and two equivalent Si(4) atoms. In the third Mg site, Mg(3) is bonded in a 7-coordinate geometry to one Si(1), one Si(3), two equivalent Si(2), and three equivalent Si(4) atoms. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 7-coordinate geometry to one Mg(2), one Mg(3), two equivalent Mg(1), one Si(1), one Si(2), and one Si(3) atom. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to two equivalent Mg(2), two equivalent Mg(3), one Si(1), one Si(3), and two equivalent Si(4) atoms. In the third Si site, Si(3) is bonded in a 8-coordinate geometry to one Mg(3), two equivalent Mg(1), two equivalent Mg(2), one Si(1), one Si(2), and one Si(4) atom. In the fourth Si site, Si(4) is bonded in a 10-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), three equivalent Mg(3), one Si(3), and two equivalent Si(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg3Si4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.445
_cell_length_b   6.978
_cell_length_c   7.864
_cell_angle_alpha   115.330
_cell_angle_beta   82.835
_cell_angle_gamma   110.727
_symmetry_Int_Tables_number   1
_cell_volume   252.475
_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  0.216  0.348  0.975  1.0
  Mg  Mg1  1  0.784  0.652  0.025  1.0
  Mg  Mg2  1  0.784  0.038  0.397  1.0
  Mg  Mg3  1  0.864  0.475  0.322  1.0
  Mg  Mg4  1  0.136  0.525  0.678  1.0
  Mg  Mg5  1  0.216  0.962  0.603  1.0
  Si  Si6  1  0.726  0.027  0.030  1.0
  Si  Si7  1  0.306  0.215  0.330  1.0
  Si  Si8  1  0.740  0.201  0.789  1.0
  Si  Si9  1  0.569  0.389  0.645  1.0
  Si  Si10  1  0.260  0.799  0.211  1.0
  Si  Si11  1  0.694  0.785  0.670  1.0
  Si  Si12  1  0.274  0.973  0.970  1.0
  Si  Si13  1  0.431  0.611  0.355  1.0
[/CIF]
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