The material described by Mg5Si6 crystallizes in the monoclinic C2/m space group. There are five inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a rectangular see-saw-like geometry to one Si(1), one Si(2), one Si(3), and one Si(4) atom. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to one Si(6), two equivalent Si(1), and three equivalent Si(3) atoms. In the third Mg site, Mg(3) is bonded in a 8-coordinate geometry to two equivalent Si(2), two equivalent Si(4), and four equivalent Si(5) atoms. In the fourth Mg site, Mg(4) is bonded in a 8-coordinate geometry to two equivalent Si(1), two equivalent Si(2), two equivalent Si(3), and two equivalent Si(6) atoms. In the fifth Mg site, Mg(5) is bonded in a 8-coordinate geometry to two equivalent Si(1), two equivalent Si(2), two equivalent Si(4), and two equivalent Si(5) atoms. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Mg(1), two equivalent Mg(2), two equivalent Mg(4), two equivalent Mg(5), one Si(2), and one Si(6) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to one Mg(1), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(5), one Si(1), and one Si(5) atom. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one Mg(1), two equivalent Mg(4), three equivalent Mg(2), and three equivalent Si(6) atoms. In the fourth Si site, Si(4) is bonded in a 7-coordinate geometry to one Mg(1), two equivalent Mg(3), two equivalent Mg(5), one Si(4), and one Si(5) atom. In the fifth Si site, Si(5) is bonded in a 9-coordinate geometry to two equivalent Mg(5), four equivalent Mg(3), one Si(2), one Si(4), and one Si(5) atom. In the sixth Si site, Si(6) is bonded in a 7-coordinate geometry to one Mg(2), two equivalent Mg(4), one Si(1), and three equivalent Si(3) atoms. is represented by the CIF card [CIF]
data_Mg5Si6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   14.632
_cell_length_b   14.632
_cell_length_c   6.839
_cell_angle_alpha   86.748
_cell_angle_beta   86.748
_cell_angle_gamma   16.338
_symmetry_Int_Tables_number   1
_cell_volume   411.228
_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  0.368  0.368  0.160  1.0
  Mg  Mg1  1  0.632  0.632  0.840  1.0
  Mg  Mg2  1  0.202  0.202  0.013  1.0
  Mg  Mg3  1  0.043  0.043  0.676  1.0
  Mg  Mg4  1  0.957  0.957  0.324  1.0
  Mg  Mg5  1  0.798  0.798  0.987  1.0
  Mg  Mg6  1  0.163  0.163  0.518  1.0
  Mg  Mg7  1  0.081  0.081  0.172  1.0
  Mg  Mg8  1  0.919  0.919  0.828  1.0
  Mg  Mg9  1  0.837  0.837  0.482  1.0
  Si  Si10  1  0.346  0.346  0.786  1.0
  Si  Si11  1  0.400  0.400  0.513  1.0
  Si  Si12  1  0.600  0.600  0.487  1.0
  Si  Si13  1  0.654  0.654  0.214  1.0
  Si  Si14  1  0.275  0.275  0.292  1.0
  Si  Si15  1  0.458  0.458  0.023  1.0
  Si  Si16  1  0.474  0.474  0.658  1.0
  Si  Si17  1  0.725  0.725  0.708  1.0
  Si  Si18  1  0.270  0.270  0.658  1.0
  Si  Si19  1  0.526  0.526  0.342  1.0
  Si  Si20  1  0.542  0.542  0.977  1.0
  Si  Si21  1  0.730  0.730  0.342  1.0
[/CIF]
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The material described by Mg5Si6 crystallizes in the monoclinic C2/m space group. There are five inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a rectangular see-saw-like geometry to one Si(1), one Si(2), one Si(3), and one Si(4) atom. In the second Mg site, Mg(2) is bonded in a 6-coordinate geometry to one Si(6), two equivalent Si(1), and three equivalent Si(3) atoms. In the third Mg site, Mg(3) is bonded in a 8-coordinate geometry to two equivalent Si(2), two equivalent Si(4), and four equivalent Si(5) atoms. In the fourth Mg site, Mg(4) is bonded in a 8-coordinate geometry to two equivalent Si(1), two equivalent Si(2), two equivalent Si(3), and two equivalent Si(6) atoms. In the fifth Mg site, Mg(5) is bonded in a 8-coordinate geometry to two equivalent Si(1), two equivalent Si(2), two equivalent Si(4), and two equivalent Si(5) atoms. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to one Mg(1), two equivalent Mg(2), two equivalent Mg(4), two equivalent Mg(5), one Si(2), and one Si(6) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to one Mg(1), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(5), one Si(1), and one Si(5) atom. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one Mg(1), two equivalent Mg(4), three equivalent Mg(2), and three equivalent Si(6) atoms. In the fourth Si site, Si(4) is bonded in a 7-coordinate geometry to one Mg(1), two equivalent Mg(3), two equivalent Mg(5), one Si(4), and one Si(5) atom. In the fifth Si site, Si(5) is bonded in a 9-coordinate geometry to two equivalent Mg(5), four equivalent Mg(3), one Si(2), one Si(4), and one Si(5) atom. In the sixth Si site, Si(6) is bonded in a 7-coordinate geometry to one Mg(2), two equivalent Mg(4), one Si(1), and three equivalent Si(3) atoms. is represented by the CIF card [CIF]
data_Mg5Si6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   14.632
_cell_length_b   14.632
_cell_length_c   6.839
_cell_angle_alpha   86.748
_cell_angle_beta   86.748
_cell_angle_gamma   16.338
_symmetry_Int_Tables_number   1
_cell_volume   411.228
_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  0.368  0.368  0.160  1.0
  Mg  Mg1  1  0.632  0.632  0.840  1.0
  Mg  Mg2  1  0.202  0.202  0.013  1.0
  Mg  Mg3  1  0.043  0.043  0.676  1.0
  Mg  Mg4  1  0.957  0.957  0.324  1.0
  Mg  Mg5  1  0.798  0.798  0.987  1.0
  Mg  Mg6  1  0.163  0.163  0.518  1.0
  Mg  Mg7  1  0.081  0.081  0.172  1.0
  Mg  Mg8  1  0.919  0.919  0.828  1.0
  Mg  Mg9  1  0.837  0.837  0.482  1.0
  Si  Si10  1  0.346  0.346  0.786  1.0
  Si  Si11  1  0.400  0.400  0.513  1.0
  Si  Si12  1  0.600  0.600  0.487  1.0
  Si  Si13  1  0.654  0.654  0.214  1.0
  Si  Si14  1  0.275  0.275  0.292  1.0
  Si  Si15  1  0.458  0.458  0.023  1.0
  Si  Si16  1  0.474  0.474  0.658  1.0
  Si  Si17  1  0.725  0.725  0.708  1.0
  Si  Si18  1  0.270  0.270  0.658  1.0
  Si  Si19  1  0.526  0.526  0.342  1.0
  Si  Si20  1  0.542  0.542  0.977  1.0
  Si  Si21  1  0.730  0.730  0.342  1.0
[/CIF]
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