The crystal structure described by Mg4Si3 is Magnesium tetraboride-like structured and 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 3-coordinate geometry to one 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(2) and two equivalent Si(3) atoms. In the third Mg site, Mg(3) is bonded in a 3-coordinate geometry to one Si(2), one Si(3), and two equivalent Si(1) atoms. In the fourth Mg site, Mg(4) is bonded in a 6-coordinate geometry to two equivalent 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 7-coordinate geometry to two equivalent Mg(3), two equivalent Mg(4), 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 one Mg(1), one Mg(3), two equivalent Mg(2), two equivalent Mg(4), one Si(1), and one Si(2) atom. 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), two equivalent Mg(4), and one Si(1) atom. is represented by the CIF file [CIF]
data_Mg4Si3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.840
_cell_length_b   6.868
_cell_length_c   7.207
_cell_angle_alpha   107.708
_cell_angle_beta   84.715
_cell_angle_gamma   117.723
_symmetry_Int_Tables_number   1
_cell_volume   284.999
_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  0.227  0.237  0.019  1.0
  Mg  Mg1  1  0.144  0.244  0.623  1.0
  Mg  Mg2  1  0.230  0.708  0.971  1.0
  Mg  Mg3  1  0.213  0.591  0.380  1.0
  Mg  Mg4  1  0.773  0.763  0.981  1.0
  Mg  Mg5  1  0.856  0.756  0.377  1.0
  Mg  Mg6  1  0.787  0.409  0.620  1.0
  Mg  Mg7  1  0.770  0.292  0.029  1.0
  Si  Si8  1  0.503  0.011  0.323  1.0
  Si  Si9  1  0.521  0.642  0.663  1.0
  Si  Si10  1  0.105  0.869  0.706  1.0
  Si  Si11  1  0.895  0.131  0.294  1.0
  Si  Si12  1  0.497  0.989  0.677  1.0
  Si  Si13  1  0.479  0.358  0.337  1.0
[/CIF]
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The crystal structure described by Mg4Si3 is Magnesium tetraboride-like structured and 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 3-coordinate geometry to one 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(2) and two equivalent Si(3) atoms. In the third Mg site, Mg(3) is bonded in a 3-coordinate geometry to one Si(2), one Si(3), and two equivalent Si(1) atoms. In the fourth Mg site, Mg(4) is bonded in a 6-coordinate geometry to two equivalent 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 7-coordinate geometry to two equivalent Mg(3), two equivalent Mg(4), 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 one Mg(1), one Mg(3), two equivalent Mg(2), two equivalent Mg(4), one Si(1), and one Si(2) atom. 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), two equivalent Mg(4), and one Si(1) atom. is represented by the CIF file [CIF]
data_Mg4Si3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.840
_cell_length_b   6.868
_cell_length_c   7.207
_cell_angle_alpha   107.708
_cell_angle_beta   84.715
_cell_angle_gamma   117.723
_symmetry_Int_Tables_number   1
_cell_volume   284.999
_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  0.227  0.237  0.019  1.0
  Mg  Mg1  1  0.144  0.244  0.623  1.0
  Mg  Mg2  1  0.230  0.708  0.971  1.0
  Mg  Mg3  1  0.213  0.591  0.380  1.0
  Mg  Mg4  1  0.773  0.763  0.981  1.0
  Mg  Mg5  1  0.856  0.756  0.377  1.0
  Mg  Mg6  1  0.787  0.409  0.620  1.0
  Mg  Mg7  1  0.770  0.292  0.029  1.0
  Si  Si8  1  0.503  0.011  0.323  1.0
  Si  Si9  1  0.521  0.642  0.663  1.0
  Si  Si10  1  0.105  0.869  0.706  1.0
  Si  Si11  1  0.895  0.131  0.294  1.0
  Si  Si12  1  0.497  0.989  0.677  1.0
  Si  Si13  1  0.479  0.358  0.337  1.0
[/CIF]
.