The compound described by Ag7Al2Si crystallizes in the monoclinic P2_1 space group. There are seven inequivalent Ag sites. In the first Ag site, Ag(1) is bonded in a 12-coordinate geometry to one Ag(5), one Ag(6), two equivalent Ag(2), two equivalent Ag(3), two equivalent Ag(7), one Al(1), two equivalent Al(2), and one Si(1) atom. In the second Ag site, Ag(2) is bonded in a 12-coordinate geometry to one Ag(3), one Ag(4), two equivalent Ag(1), two equivalent Ag(6), two equivalent Ag(7), one Al(1), two equivalent Al(2), and one Si(1) atom. In the third Ag site, Ag(3) is bonded in a 12-coordinate geometry to one Ag(2), one Ag(4), one Ag(7), two equivalent Ag(1), two equivalent Ag(5), one Al(1), two equivalent Al(2), and two equivalent Si(1) atoms. In the fourth Ag site, Ag(4) is bonded in a 12-coordinate geometry to one Ag(2), one Ag(3), one Ag(7), two equivalent Ag(5), two equivalent Ag(6), one Al(2), two equivalent Al(1), and two equivalent Si(1) atoms. In the fifth Ag site, Ag(5) is bonded in a 12-coordinate geometry to one Ag(1), one Ag(6), one Ag(7), two equivalent Ag(3), two equivalent Ag(4), one Al(2), two equivalent Al(1), and two equivalent Si(1) atoms. In the sixth Ag site, Ag(6) is bonded in a 12-coordinate geometry to one Ag(1), one Ag(5), two equivalent Ag(2), two equivalent Ag(4), two equivalent Ag(7), one Al(2), two equivalent Al(1), and one Si(1) atom. In the seventh Ag site, Ag(7) is bonded in a distorted trigonal planar geometry to one Ag(3), one Ag(4), one Ag(5), two equivalent Ag(1), two equivalent Ag(2), two equivalent Ag(6), one Al(1), and two equivalent Al(2) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one Ag(1), one Ag(2), one Ag(3), one Ag(7), two equivalent Ag(4), two equivalent Ag(5), two equivalent Ag(6), and two equivalent Si(1) atoms to form distorted AlSi2Ag10 cuboctahedra that share corners with two equivalent Al(1)Si2Ag10 cuboctahedra, corners with four equivalent Al(2)SiAg11 cuboctahedra, faces with two equivalent Al(1)Si2Ag10 cuboctahedra, and faces with four equivalent Al(2)SiAg11 cuboctahedra. In the second Al site, Al(2) is bonded to one Ag(4), one Ag(5), one Ag(6), two equivalent Ag(1), two equivalent Ag(2), two equivalent Ag(3), two equivalent Ag(7), and one Si(1) atom to form distorted AlSiAg11 cuboctahedra that share corners with two equivalent Al(2)SiAg11 cuboctahedra, corners with four equivalent Al(1)Si2Ag10 cuboctahedra, faces with two equivalent Al(2)SiAg11 cuboctahedra, and faces with four equivalent Al(1)Si2Ag10 cuboctahedra. Si(1) is bonded in a 12-coordinate geometry to one Ag(1), one Ag(2), one Ag(6), two equivalent Ag(3), two equivalent Ag(4), two equivalent Ag(5), one Al(2), and two equivalent Al(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Al2SiAg7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.045
_cell_length_b   6.970
_cell_length_c   7.015
_cell_angle_alpha   88.815
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   344.396
_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
  Al  Al0  1  0.192  0.189  0.442  1.0
  Al  Al1  1  0.692  0.811  0.558  1.0
  Al  Al2  1  0.815  0.310  0.935  1.0
  Al  Al3  1  0.315  0.690  0.065  1.0
  Si  Si4  1  0.437  0.937  0.312  1.0
  Si  Si5  1  0.937  0.063  0.688  1.0
  Ag  Ag6  1  0.958  0.705  0.874  1.0
  Ag  Ag7  1  0.700  0.626  0.207  1.0
  Ag  Ag8  1  0.621  0.957  0.954  1.0
  Ag  Ag9  1  0.458  0.295  0.126  1.0
  Ag  Ag10  1  0.200  0.374  0.793  1.0
  Ag  Ag11  1  0.121  0.043  0.046  1.0
  Ag  Ag12  1  0.045  0.798  0.376  1.0
  Ag  Ag13  1  0.296  0.877  0.704  1.0
  Ag  Ag14  1  0.371  0.545  0.450  1.0
  Ag  Ag15  1  0.545  0.202  0.624  1.0
  Ag  Ag16  1  0.796  0.123  0.296  1.0
  Ag  Ag17  1  0.871  0.455  0.550  1.0
  Ag  Ag18  1  0.565  0.567  0.816  1.0
  Ag  Ag19  1  0.065  0.433  0.184  1.0
[/CIF]
.
The compound described by Ag7Al2Si crystallizes in the monoclinic P2_1 space group. There are seven inequivalent Ag sites. In the first Ag site, Ag(1) is bonded in a 12-coordinate geometry to one Ag(5), one Ag(6), two equivalent Ag(2), two equivalent Ag(3), two equivalent Ag(7), one Al(1), two equivalent Al(2), and one Si(1) atom. In the second Ag site, Ag(2) is bonded in a 12-coordinate geometry to one Ag(3), one Ag(4), two equivalent Ag(1), two equivalent Ag(6), two equivalent Ag(7), one Al(1), two equivalent Al(2), and one Si(1) atom. In the third Ag site, Ag(3) is bonded in a 12-coordinate geometry to one Ag(2), one Ag(4), one Ag(7), two equivalent Ag(1), two equivalent Ag(5), one Al(1), two equivalent Al(2), and two equivalent Si(1) atoms. In the fourth Ag site, Ag(4) is bonded in a 12-coordinate geometry to one Ag(2), one Ag(3), one Ag(7), two equivalent Ag(5), two equivalent Ag(6), one Al(2), two equivalent Al(1), and two equivalent Si(1) atoms. In the fifth Ag site, Ag(5) is bonded in a 12-coordinate geometry to one Ag(1), one Ag(6), one Ag(7), two equivalent Ag(3), two equivalent Ag(4), one Al(2), two equivalent Al(1), and two equivalent Si(1) atoms. In the sixth Ag site, Ag(6) is bonded in a 12-coordinate geometry to one Ag(1), one Ag(5), two equivalent Ag(2), two equivalent Ag(4), two equivalent Ag(7), one Al(2), two equivalent Al(1), and one Si(1) atom. In the seventh Ag site, Ag(7) is bonded in a distorted trigonal planar geometry to one Ag(3), one Ag(4), one Ag(5), two equivalent Ag(1), two equivalent Ag(2), two equivalent Ag(6), one Al(1), and two equivalent Al(2) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one Ag(1), one Ag(2), one Ag(3), one Ag(7), two equivalent Ag(4), two equivalent Ag(5), two equivalent Ag(6), and two equivalent Si(1) atoms to form distorted AlSi2Ag10 cuboctahedra that share corners with two equivalent Al(1)Si2Ag10 cuboctahedra, corners with four equivalent Al(2)SiAg11 cuboctahedra, faces with two equivalent Al(1)Si2Ag10 cuboctahedra, and faces with four equivalent Al(2)SiAg11 cuboctahedra. In the second Al site, Al(2) is bonded to one Ag(4), one Ag(5), one Ag(6), two equivalent Ag(1), two equivalent Ag(2), two equivalent Ag(3), two equivalent Ag(7), and one Si(1) atom to form distorted AlSiAg11 cuboctahedra that share corners with two equivalent Al(2)SiAg11 cuboctahedra, corners with four equivalent Al(1)Si2Ag10 cuboctahedra, faces with two equivalent Al(2)SiAg11 cuboctahedra, and faces with four equivalent Al(1)Si2Ag10 cuboctahedra. Si(1) is bonded in a 12-coordinate geometry to one Ag(1), one Ag(2), one Ag(6), two equivalent Ag(3), two equivalent Ag(4), two equivalent Ag(5), one Al(2), and two equivalent Al(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Al2SiAg7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.045
_cell_length_b   6.970
_cell_length_c   7.015
_cell_angle_alpha   88.815
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   344.396
_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
  Al  Al0  1  0.192  0.189  0.442  1.0
  Al  Al1  1  0.692  0.811  0.558  1.0
  Al  Al2  1  0.815  0.310  0.935  1.0
  Al  Al3  1  0.315  0.690  0.065  1.0
  Si  Si4  1  0.437  0.937  0.312  1.0
  Si  Si5  1  0.937  0.063  0.688  1.0
  Ag  Ag6  1  0.958  0.705  0.874  1.0
  Ag  Ag7  1  0.700  0.626  0.207  1.0
  Ag  Ag8  1  0.621  0.957  0.954  1.0
  Ag  Ag9  1  0.458  0.295  0.126  1.0
  Ag  Ag10  1  0.200  0.374  0.793  1.0
  Ag  Ag11  1  0.121  0.043  0.046  1.0
  Ag  Ag12  1  0.045  0.798  0.376  1.0
  Ag  Ag13  1  0.296  0.877  0.704  1.0
  Ag  Ag14  1  0.371  0.545  0.450  1.0
  Ag  Ag15  1  0.545  0.202  0.624  1.0
  Ag  Ag16  1  0.796  0.123  0.296  1.0
  Ag  Ag17  1  0.871  0.455  0.550  1.0
  Ag  Ag18  1  0.565  0.567  0.816  1.0
  Ag  Ag19  1  0.065  0.433  0.184  1.0
[/CIF]
.