The compound described by Mg5Si6 crystallizes in the monoclinic P2_1/m space group. There are five inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 4-coordinate 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(5), 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), three equivalent Si(4), and three equivalent Si(6) 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(5) 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(6) 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(5) 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(6) 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), one Si(5), and two equivalent Si(3) atoms. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to one Mg(1), two equivalent Mg(5), three equivalent Mg(3), and three equivalent Si(6) atoms. In the fifth Si site, Si(5) is bonded in a 7-coordinate geometry to one Mg(2), two equivalent Mg(4), one Si(1), one Si(3), and two equivalent Si(5) atoms. In the sixth Si site, Si(6) is bonded in a 9-coordinate geometry to two equivalent Mg(5), three equivalent Mg(3), one Si(2), and three equivalent Si(4) atoms. is represented by the CIF card [CIF]
data_Mg5Si6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.000
_cell_length_b   6.925
_cell_length_c   14.663
_cell_angle_alpha   82.995
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   403.119
_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  0.250  0.386  0.758  1.0
  Mg  Mg1  1  0.750  0.614  0.242  1.0
  Mg  Mg2  1  0.250  0.734  0.379  1.0
  Mg  Mg3  1  0.250  0.471  0.090  1.0
  Mg  Mg4  1  0.750  0.529  0.910  1.0
  Mg  Mg5  1  0.750  0.266  0.621  1.0
  Mg  Mg6  1  0.250  0.284  0.328  1.0
  Mg  Mg7  1  0.250  0.953  0.171  1.0
  Mg  Mg8  1  0.750  0.047  0.829  1.0
  Mg  Mg9  1  0.750  0.716  0.672  1.0
  Si  Si10  1  0.250  0.024  0.692  1.0
  Si  Si11  1  0.250  0.746  0.807  1.0
  Si  Si12  1  0.750  0.254  0.193  1.0
  Si  Si13  1  0.750  0.976  0.308  1.0
  Si  Si14  1  0.250  0.552  0.555  1.0
  Si  Si15  1  0.250  0.212  0.942  1.0
  Si  Si16  1  0.750  0.788  0.058  1.0
  Si  Si17  1  0.750  0.077  0.460  1.0
  Si  Si18  1  0.250  0.923  0.540  1.0
  Si  Si19  1  0.250  0.844  0.957  1.0
  Si  Si20  1  0.750  0.156  0.043  1.0
  Si  Si21  1  0.750  0.448  0.445  1.0
[/CIF]
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The compound described by Mg5Si6 crystallizes in the monoclinic P2_1/m space group. There are five inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 4-coordinate 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(5), 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), three equivalent Si(4), and three equivalent Si(6) 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(5) 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(6) 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(5) 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(6) 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), one Si(5), and two equivalent Si(3) atoms. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to one Mg(1), two equivalent Mg(5), three equivalent Mg(3), and three equivalent Si(6) atoms. In the fifth Si site, Si(5) is bonded in a 7-coordinate geometry to one Mg(2), two equivalent Mg(4), one Si(1), one Si(3), and two equivalent Si(5) atoms. In the sixth Si site, Si(6) is bonded in a 9-coordinate geometry to two equivalent Mg(5), three equivalent Mg(3), one Si(2), and three equivalent Si(4) atoms. is represented by the CIF card [CIF]
data_Mg5Si6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.000
_cell_length_b   6.925
_cell_length_c   14.663
_cell_angle_alpha   82.995
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   403.119
_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  0.250  0.386  0.758  1.0
  Mg  Mg1  1  0.750  0.614  0.242  1.0
  Mg  Mg2  1  0.250  0.734  0.379  1.0
  Mg  Mg3  1  0.250  0.471  0.090  1.0
  Mg  Mg4  1  0.750  0.529  0.910  1.0
  Mg  Mg5  1  0.750  0.266  0.621  1.0
  Mg  Mg6  1  0.250  0.284  0.328  1.0
  Mg  Mg7  1  0.250  0.953  0.171  1.0
  Mg  Mg8  1  0.750  0.047  0.829  1.0
  Mg  Mg9  1  0.750  0.716  0.672  1.0
  Si  Si10  1  0.250  0.024  0.692  1.0
  Si  Si11  1  0.250  0.746  0.807  1.0
  Si  Si12  1  0.750  0.254  0.193  1.0
  Si  Si13  1  0.750  0.976  0.308  1.0
  Si  Si14  1  0.250  0.552  0.555  1.0
  Si  Si15  1  0.250  0.212  0.942  1.0
  Si  Si16  1  0.750  0.788  0.058  1.0
  Si  Si17  1  0.750  0.077  0.460  1.0
  Si  Si18  1  0.250  0.923  0.540  1.0
  Si  Si19  1  0.250  0.844  0.957  1.0
  Si  Si20  1  0.750  0.156  0.043  1.0
  Si  Si21  1  0.750  0.448  0.445  1.0
[/CIF]
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