The compound described by Mg17Al11Si is gamma-brass-derived structured and crystallizes in the monoclinic Cm space group. There are eleven inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 12-coordinate geometry to one Mg(5), two equivalent Mg(11), two equivalent Mg(6), two equivalent Mg(7), two equivalent Al(2), two equivalent Al(4), and one Si(1) atom. In the second Mg site, Mg(2) is bonded in a 12-coordinate geometry to one Mg(4), two equivalent Mg(10), two equivalent Mg(6), two equivalent Mg(8), one Al(1), two equivalent Al(2), and two equivalent Al(3) atoms. In the third Mg site, Mg(3) is bonded in a 16-coordinate geometry to one Mg(4), one Mg(5), two equivalent Mg(9), one Al(1), two equivalent Al(2), two equivalent Al(3), two equivalent Al(4), two equivalent Al(5), two equivalent Al(6), and one Si(1) atom. In the fourth Mg site, Mg(4) is bonded in a 10-coordinate geometry to one Mg(2), one Mg(3), two equivalent Mg(7), two equivalent Al(2), two equivalent Al(4), and two equivalent Al(6) atoms. In the fifth Mg site, Mg(5) is bonded in a 10-coordinate geometry to one Mg(1), one Mg(3), two equivalent Mg(8), two equivalent Al(2), two equivalent Al(3), and two equivalent Al(5) atoms. In the sixth Mg site, Mg(6) is bonded in a 12-coordinate geometry to one Mg(1), one Mg(10), one Mg(11), one Mg(2), one Mg(7), one Mg(8), one Mg(9), one Al(1), one Al(2), one Al(5), one Al(6), and one Si(1) atom. In the seventh Mg site, Mg(7) is bonded in a 12-coordinate geometry to one Mg(1), one Mg(10), one Mg(4), one Mg(6), one Mg(8), two equivalent Mg(11), one Al(3), one Al(4), one Al(5), one Al(6), and one Si(1) atom. In the eighth Mg site, Mg(8) is bonded in a 12-coordinate geometry to one Mg(11), one Mg(2), one Mg(5), one Mg(6), one Mg(7), two equivalent Mg(10), one Al(1), one Al(3), one Al(4), one Al(5), and one Al(6) atom. In the ninth Mg site, Mg(9) is bonded in a 10-coordinate geometry to one Mg(10), one Mg(11), one Mg(3), one Mg(6), one Al(1), one Al(3), one Al(4), one Al(5), one Al(6), and one Si(1) atom. In the tenth Mg site, Mg(10) is bonded in a 12-coordinate geometry to one Mg(11), one Mg(2), one Mg(6), one Mg(7), one Mg(9), two equivalent Mg(8), one Al(2), one Al(3), one Al(4), and two equivalent Al(6) atoms. In the eleventh Mg site, Mg(11) is bonded in a 12-coordinate geometry to one Mg(1), one Mg(10), one Mg(6), one Mg(8), one Mg(9), two equivalent Mg(7), one Al(2), one Al(3), one Al(4), and two equivalent Al(5) atoms. There are six inequivalent Al sites. In the first Al site, Al(1) is bonded in a 11-coordinate geometry to one Mg(2), one Mg(3), two equivalent Mg(6), two equivalent Mg(8), two equivalent Mg(9), two equivalent Al(4), and one Si(1) atom. In the second Al site, Al(2) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(10), one Mg(11), one Mg(2), one Mg(3), one Mg(4), one Mg(5), one Mg(6), one Al(2), one Al(5), and one Al(6) atom. In the third Al site, Al(3) is bonded in a 11-coordinate geometry to one Mg(10), one Mg(11), one Mg(2), one Mg(3), one Mg(5), one Mg(7), one Mg(8), one Mg(9), one Al(3), one Al(5), and one Si(1) atom. In the fourth Al site, Al(4) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(10), one Mg(11), one Mg(3), one Mg(4), one Mg(7), one Mg(8), one Mg(9), one Al(1), one Al(4), and one Al(6) atom. In the fifth Al site, Al(5) is bonded in a 11-coordinate geometry to one Mg(3), one Mg(5), one Mg(6), one Mg(7), one Mg(8), one Mg(9), two equivalent Mg(11), one Al(2), one Al(3), and one Al(6) atom. In the sixth Al site, Al(6) is bonded in a 11-coordinate geometry to one Mg(3), one Mg(4), one Mg(6), one Mg(7), one Mg(8), one Mg(9), two equivalent Mg(10), one Al(2), one Al(4), and one Al(5) atom. Si(1) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(3), two equivalent Mg(6), two equivalent Mg(7), two equivalent Mg(9), one Al(1), and two equivalent Al(3) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg17Al11Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.118
_cell_length_b   9.118
_cell_length_c   9.079
_cell_angle_alpha   70.565
_cell_angle_beta   70.565
_cell_angle_gamma   109.479
_symmetry_Int_Tables_number   1
_cell_volume   581.567
_cell_formula_units_Z   1
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  0.604  0.604  0.716  1.0
  Mg  Mg1  1  0.315  0.315  0.286  1.0
  Mg  Mg2  1  0.001  0.001  1.000  1.0
  Mg  Mg3  1  0.001  0.001  0.343  1.0
  Mg  Mg4  1  0.345  0.345  0.655  1.0
  Mg  Mg5  1  0.396  0.683  0.002  1.0
  Mg  Mg6  1  0.686  0.999  0.603  1.0
  Mg  Mg7  1  0.287  0.603  0.397  1.0
  Mg  Mg8  1  0.654  0.999  0.000  1.0
  Mg  Mg9  1  0.999  0.396  0.317  1.0
  Mg  Mg10  1  0.316  0.714  0.684  1.0
  Mg  Mg11  1  0.714  0.316  0.684  1.0
  Mg  Mg12  1  0.396  0.999  0.317  1.0
  Mg  Mg13  1  0.999  0.654  0.000  1.0
  Mg  Mg14  1  0.603  0.287  0.397  1.0
  Mg  Mg15  1  0.999  0.686  0.603  1.0
  Mg  Mg16  1  0.683  0.396  0.002  1.0
  Al  Al17  1  0.637  0.637  0.171  1.0
  Al  Al18  1  0.186  0.366  0.999  1.0
  Al  Al19  1  0.996  0.180  0.637  1.0
  Al  Al20  1  0.635  0.819  0.364  1.0
  Al  Al21  1  0.999  0.365  0.816  1.0
  Al  Al22  1  0.815  0.181  0.186  1.0
  Al  Al23  1  0.181  0.815  0.186  1.0
  Al  Al24  1  0.365  0.999  0.816  1.0
  Al  Al25  1  0.819  0.635  0.364  1.0
  Al  Al26  1  0.180  0.996  0.637  1.0
  Al  Al27  1  0.366  0.186  0.999  1.0
  Si  Si28  1  0.816  0.816  0.817  1.0
[/CIF]
.
The compound described by Mg17Al11Si is gamma-brass-derived structured and crystallizes in the monoclinic Cm space group. There are eleven inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 12-coordinate geometry to one Mg(5), two equivalent Mg(11), two equivalent Mg(6), two equivalent Mg(7), two equivalent Al(2), two equivalent Al(4), and one Si(1) atom. In the second Mg site, Mg(2) is bonded in a 12-coordinate geometry to one Mg(4), two equivalent Mg(10), two equivalent Mg(6), two equivalent Mg(8), one Al(1), two equivalent Al(2), and two equivalent Al(3) atoms. In the third Mg site, Mg(3) is bonded in a 16-coordinate geometry to one Mg(4), one Mg(5), two equivalent Mg(9), one Al(1), two equivalent Al(2), two equivalent Al(3), two equivalent Al(4), two equivalent Al(5), two equivalent Al(6), and one Si(1) atom. In the fourth Mg site, Mg(4) is bonded in a 10-coordinate geometry to one Mg(2), one Mg(3), two equivalent Mg(7), two equivalent Al(2), two equivalent Al(4), and two equivalent Al(6) atoms. In the fifth Mg site, Mg(5) is bonded in a 10-coordinate geometry to one Mg(1), one Mg(3), two equivalent Mg(8), two equivalent Al(2), two equivalent Al(3), and two equivalent Al(5) atoms. In the sixth Mg site, Mg(6) is bonded in a 12-coordinate geometry to one Mg(1), one Mg(10), one Mg(11), one Mg(2), one Mg(7), one Mg(8), one Mg(9), one Al(1), one Al(2), one Al(5), one Al(6), and one Si(1) atom. In the seventh Mg site, Mg(7) is bonded in a 12-coordinate geometry to one Mg(1), one Mg(10), one Mg(4), one Mg(6), one Mg(8), two equivalent Mg(11), one Al(3), one Al(4), one Al(5), one Al(6), and one Si(1) atom. In the eighth Mg site, Mg(8) is bonded in a 12-coordinate geometry to one Mg(11), one Mg(2), one Mg(5), one Mg(6), one Mg(7), two equivalent Mg(10), one Al(1), one Al(3), one Al(4), one Al(5), and one Al(6) atom. In the ninth Mg site, Mg(9) is bonded in a 10-coordinate geometry to one Mg(10), one Mg(11), one Mg(3), one Mg(6), one Al(1), one Al(3), one Al(4), one Al(5), one Al(6), and one Si(1) atom. In the tenth Mg site, Mg(10) is bonded in a 12-coordinate geometry to one Mg(11), one Mg(2), one Mg(6), one Mg(7), one Mg(9), two equivalent Mg(8), one Al(2), one Al(3), one Al(4), and two equivalent Al(6) atoms. In the eleventh Mg site, Mg(11) is bonded in a 12-coordinate geometry to one Mg(1), one Mg(10), one Mg(6), one Mg(8), one Mg(9), two equivalent Mg(7), one Al(2), one Al(3), one Al(4), and two equivalent Al(5) atoms. There are six inequivalent Al sites. In the first Al site, Al(1) is bonded in a 11-coordinate geometry to one Mg(2), one Mg(3), two equivalent Mg(6), two equivalent Mg(8), two equivalent Mg(9), two equivalent Al(4), and one Si(1) atom. In the second Al site, Al(2) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(10), one Mg(11), one Mg(2), one Mg(3), one Mg(4), one Mg(5), one Mg(6), one Al(2), one Al(5), and one Al(6) atom. In the third Al site, Al(3) is bonded in a 11-coordinate geometry to one Mg(10), one Mg(11), one Mg(2), one Mg(3), one Mg(5), one Mg(7), one Mg(8), one Mg(9), one Al(3), one Al(5), and one Si(1) atom. In the fourth Al site, Al(4) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(10), one Mg(11), one Mg(3), one Mg(4), one Mg(7), one Mg(8), one Mg(9), one Al(1), one Al(4), and one Al(6) atom. In the fifth Al site, Al(5) is bonded in a 11-coordinate geometry to one Mg(3), one Mg(5), one Mg(6), one Mg(7), one Mg(8), one Mg(9), two equivalent Mg(11), one Al(2), one Al(3), and one Al(6) atom. In the sixth Al site, Al(6) is bonded in a 11-coordinate geometry to one Mg(3), one Mg(4), one Mg(6), one Mg(7), one Mg(8), one Mg(9), two equivalent Mg(10), one Al(2), one Al(4), and one Al(5) atom. Si(1) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(3), two equivalent Mg(6), two equivalent Mg(7), two equivalent Mg(9), one Al(1), and two equivalent Al(3) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg17Al11Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.118
_cell_length_b   9.118
_cell_length_c   9.079
_cell_angle_alpha   70.565
_cell_angle_beta   70.565
_cell_angle_gamma   109.479
_symmetry_Int_Tables_number   1
_cell_volume   581.567
_cell_formula_units_Z   1
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  0.604  0.604  0.716  1.0
  Mg  Mg1  1  0.315  0.315  0.286  1.0
  Mg  Mg2  1  0.001  0.001  1.000  1.0
  Mg  Mg3  1  0.001  0.001  0.343  1.0
  Mg  Mg4  1  0.345  0.345  0.655  1.0
  Mg  Mg5  1  0.396  0.683  0.002  1.0
  Mg  Mg6  1  0.686  0.999  0.603  1.0
  Mg  Mg7  1  0.287  0.603  0.397  1.0
  Mg  Mg8  1  0.654  0.999  0.000  1.0
  Mg  Mg9  1  0.999  0.396  0.317  1.0
  Mg  Mg10  1  0.316  0.714  0.684  1.0
  Mg  Mg11  1  0.714  0.316  0.684  1.0
  Mg  Mg12  1  0.396  0.999  0.317  1.0
  Mg  Mg13  1  0.999  0.654  0.000  1.0
  Mg  Mg14  1  0.603  0.287  0.397  1.0
  Mg  Mg15  1  0.999  0.686  0.603  1.0
  Mg  Mg16  1  0.683  0.396  0.002  1.0
  Al  Al17  1  0.637  0.637  0.171  1.0
  Al  Al18  1  0.186  0.366  0.999  1.0
  Al  Al19  1  0.996  0.180  0.637  1.0
  Al  Al20  1  0.635  0.819  0.364  1.0
  Al  Al21  1  0.999  0.365  0.816  1.0
  Al  Al22  1  0.815  0.181  0.186  1.0
  Al  Al23  1  0.181  0.815  0.186  1.0
  Al  Al24  1  0.365  0.999  0.816  1.0
  Al  Al25  1  0.819  0.635  0.364  1.0
  Al  Al26  1  0.180  0.996  0.637  1.0
  Al  Al27  1  0.366  0.186  0.999  1.0
  Si  Si28  1  0.816  0.816  0.817  1.0
[/CIF]
.