The crystal structure described by Mg4AlSi6 crystallizes in the monoclinic C2/m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(2), one Al(1), two equivalent Si(2), two equivalent Si(3), and four equivalent Si(1) atoms. In the second Mg site, Mg(2) is bonded in a 8-coordinate geometry to one Mg(1), one Al(1), two equivalent Si(1), two equivalent Si(3), and three equivalent Si(2) atoms. Al(1) is bonded in a 8-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), and four equivalent Si(1) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Mg(2), four equivalent Mg(1), two equivalent Al(1), and one Si(3) atom. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to two equivalent Mg(1), three equivalent Mg(2), and three equivalent Si(3) atoms. In the third Si site, Si(3) is bonded in a 8-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), one Si(1), and three equivalent Si(2) atoms. is represented by the CIF file [CIF]
data_Mg4AlSi6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.377
_cell_length_b   8.377
_cell_length_c   6.735
_cell_angle_alpha   87.960
_cell_angle_beta   87.960
_cell_angle_gamma   25.346
_symmetry_Int_Tables_number   1
_cell_volume   202.194
_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  0.580  0.580  0.594  1.0
  Mg  Mg1  1  0.332  0.332  0.990  1.0
  Mg  Mg2  1  0.668  0.668  0.010  1.0
  Mg  Mg3  1  0.420  0.420  0.406  1.0
  Al  Al4  1  0.500  0.500  0.000  1.0
  Si  Si5  1  0.051  0.051  0.245  1.0
  Si  Si6  1  0.949  0.949  0.755  1.0
  Si  Si7  1  0.212  0.212  0.710  1.0
  Si  Si8  1  0.788  0.788  0.290  1.0
  Si  Si9  1  0.191  0.191  0.344  1.0
  Si  Si10  1  0.809  0.809  0.656  1.0
[/CIF]
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The crystal structure described by Mg4AlSi6 crystallizes in the monoclinic C2/m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 11-coordinate geometry to one Mg(1), one Mg(2), one Al(1), two equivalent Si(2), two equivalent Si(3), and four equivalent Si(1) atoms. In the second Mg site, Mg(2) is bonded in a 8-coordinate geometry to one Mg(1), one Al(1), two equivalent Si(1), two equivalent Si(3), and three equivalent Si(2) atoms. Al(1) is bonded in a 8-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), and four equivalent Si(1) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Mg(2), four equivalent Mg(1), two equivalent Al(1), and one Si(3) atom. In the second Si site, Si(2) is bonded in a 8-coordinate geometry to two equivalent Mg(1), three equivalent Mg(2), and three equivalent Si(3) atoms. In the third Si site, Si(3) is bonded in a 8-coordinate geometry to two equivalent Mg(1), two equivalent Mg(2), one Si(1), and three equivalent Si(2) atoms. is represented by the CIF file [CIF]
data_Mg4AlSi6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.377
_cell_length_b   8.377
_cell_length_c   6.735
_cell_angle_alpha   87.960
_cell_angle_beta   87.960
_cell_angle_gamma   25.346
_symmetry_Int_Tables_number   1
_cell_volume   202.194
_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  0.580  0.580  0.594  1.0
  Mg  Mg1  1  0.332  0.332  0.990  1.0
  Mg  Mg2  1  0.668  0.668  0.010  1.0
  Mg  Mg3  1  0.420  0.420  0.406  1.0
  Al  Al4  1  0.500  0.500  0.000  1.0
  Si  Si5  1  0.051  0.051  0.245  1.0
  Si  Si6  1  0.949  0.949  0.755  1.0
  Si  Si7  1  0.212  0.212  0.710  1.0
  Si  Si8  1  0.788  0.788  0.290  1.0
  Si  Si9  1  0.191  0.191  0.344  1.0
  Si  Si10  1  0.809  0.809  0.656  1.0
[/CIF]
.