The compound described by Y12Al7Si crystallizes in the tetragonal I4/mcm space group. There are three inequivalent Y sites. In the first Y site, Y(1) is bonded in a 4-coordinate geometry to two equivalent Al(1) and two equivalent Al(3) atoms. In the second Y site, Y(2) is bonded in a 6-coordinate geometry to one Al(1), one Al(2), three equivalent Al(3), and one Si(1) atom. In the third Y site, Y(3) is bonded in a 5-coordinate geometry to two equivalent Al(3) and three equivalent Al(1) atoms. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded in a 9-coordinate geometry to two equivalent Y(1), three equivalent Y(3), and four equivalent Y(2) atoms. In the second Al site, Al(2) is bonded in a body-centered cubic geometry to eight equivalent Y(2) atoms. In the third Al site, Al(3) is bonded in a 9-coordinate geometry to one Y(1), one Y(3), six equivalent Y(2), and one Al(3) atom. Si(1) is bonded in a 8-coordinate geometry to eight equivalent Y(2) atoms. is represented by the CIF file [CIF]
data_Y12Al7Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.254
_cell_length_b   11.254
_cell_length_c   11.254
_cell_angle_alpha   117.146
_cell_angle_beta   117.145
_cell_angle_gamma   95.020
_symmetry_Int_Tables_number   1
_cell_volume   1046.993
_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
  Y  Y0  1  0.147  0.647  0.500  1.0
  Y  Y1  1  0.853  0.353  0.500  1.0
  Y  Y2  1  0.647  0.147  0.500  1.0
  Y  Y3  1  0.353  0.853  0.500  1.0
  Y  Y4  1  0.837  0.701  0.265  1.0
  Y  Y5  1  0.163  0.299  0.735  1.0
  Y  Y6  1  0.436  0.572  0.735  1.0
  Y  Y7  1  0.701  0.436  0.864  1.0
  Y  Y8  1  0.064  0.799  0.136  1.0
  Y  Y9  1  0.564  0.428  0.265  1.0
  Y  Y10  1  0.299  0.564  0.136  1.0
  Y  Y11  1  0.936  0.201  0.864  1.0
  Y  Y12  1  0.572  0.837  0.136  1.0
  Y  Y13  1  0.663  0.928  0.864  1.0
  Y  Y14  1  0.428  0.163  0.864  1.0
  Y  Y15  1  0.337  0.072  0.136  1.0
  Y  Y16  1  0.928  0.064  0.265  1.0
  Y  Y17  1  0.072  0.936  0.735  1.0
  Y  Y18  1  0.799  0.663  0.735  1.0
  Y  Y19  1  0.201  0.337  0.265  1.0
  Y  Y20  1  0.171  0.671  0.841  1.0
  Y  Y21  1  0.829  0.329  0.159  1.0
  Y  Y22  1  0.671  0.829  0.500  1.0
  Y  Y23  1  0.329  0.171  0.500  1.0
  Al  Al24  1  0.619  0.119  0.737  1.0
  Al  Al25  1  0.381  0.881  0.263  1.0
  Al  Al26  1  0.119  0.381  0.500  1.0
  Al  Al27  1  0.881  0.619  0.500  1.0
  Al  Al28  1  0.500  0.500  0.000  1.0
  Al  Al29  1  1.000  1.000  1.000  1.0
  Al  Al30  1  0.382  0.882  0.858  1.0
  Al  Al31  1  0.618  0.118  0.142  1.0
  Al  Al32  1  0.024  0.524  0.142  1.0
  Al  Al33  1  0.882  0.024  0.500  1.0
  Al  Al34  1  0.476  0.618  0.500  1.0
  Al  Al35  1  0.976  0.476  0.858  1.0
  Al  Al36  1  0.118  0.976  0.500  1.0
  Al  Al37  1  0.524  0.382  0.500  1.0
  Si  Si38  1  0.750  0.750  1.000  1.0
  Si  Si39  1  0.250  0.250  1.000  1.0
[/CIF]
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The compound described by Y12Al7Si crystallizes in the tetragonal I4/mcm space group. There are three inequivalent Y sites. In the first Y site, Y(1) is bonded in a 4-coordinate geometry to two equivalent Al(1) and two equivalent Al(3) atoms. In the second Y site, Y(2) is bonded in a 6-coordinate geometry to one Al(1), one Al(2), three equivalent Al(3), and one Si(1) atom. In the third Y site, Y(3) is bonded in a 5-coordinate geometry to two equivalent Al(3) and three equivalent Al(1) atoms. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded in a 9-coordinate geometry to two equivalent Y(1), three equivalent Y(3), and four equivalent Y(2) atoms. In the second Al site, Al(2) is bonded in a body-centered cubic geometry to eight equivalent Y(2) atoms. In the third Al site, Al(3) is bonded in a 9-coordinate geometry to one Y(1), one Y(3), six equivalent Y(2), and one Al(3) atom. Si(1) is bonded in a 8-coordinate geometry to eight equivalent Y(2) atoms. is represented by the CIF file [CIF]
data_Y12Al7Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.254
_cell_length_b   11.254
_cell_length_c   11.254
_cell_angle_alpha   117.146
_cell_angle_beta   117.145
_cell_angle_gamma   95.020
_symmetry_Int_Tables_number   1
_cell_volume   1046.993
_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
  Y  Y0  1  0.147  0.647  0.500  1.0
  Y  Y1  1  0.853  0.353  0.500  1.0
  Y  Y2  1  0.647  0.147  0.500  1.0
  Y  Y3  1  0.353  0.853  0.500  1.0
  Y  Y4  1  0.837  0.701  0.265  1.0
  Y  Y5  1  0.163  0.299  0.735  1.0
  Y  Y6  1  0.436  0.572  0.735  1.0
  Y  Y7  1  0.701  0.436  0.864  1.0
  Y  Y8  1  0.064  0.799  0.136  1.0
  Y  Y9  1  0.564  0.428  0.265  1.0
  Y  Y10  1  0.299  0.564  0.136  1.0
  Y  Y11  1  0.936  0.201  0.864  1.0
  Y  Y12  1  0.572  0.837  0.136  1.0
  Y  Y13  1  0.663  0.928  0.864  1.0
  Y  Y14  1  0.428  0.163  0.864  1.0
  Y  Y15  1  0.337  0.072  0.136  1.0
  Y  Y16  1  0.928  0.064  0.265  1.0
  Y  Y17  1  0.072  0.936  0.735  1.0
  Y  Y18  1  0.799  0.663  0.735  1.0
  Y  Y19  1  0.201  0.337  0.265  1.0
  Y  Y20  1  0.171  0.671  0.841  1.0
  Y  Y21  1  0.829  0.329  0.159  1.0
  Y  Y22  1  0.671  0.829  0.500  1.0
  Y  Y23  1  0.329  0.171  0.500  1.0
  Al  Al24  1  0.619  0.119  0.737  1.0
  Al  Al25  1  0.381  0.881  0.263  1.0
  Al  Al26  1  0.119  0.381  0.500  1.0
  Al  Al27  1  0.881  0.619  0.500  1.0
  Al  Al28  1  0.500  0.500  0.000  1.0
  Al  Al29  1  1.000  1.000  1.000  1.0
  Al  Al30  1  0.382  0.882  0.858  1.0
  Al  Al31  1  0.618  0.118  0.142  1.0
  Al  Al32  1  0.024  0.524  0.142  1.0
  Al  Al33  1  0.882  0.024  0.500  1.0
  Al  Al34  1  0.476  0.618  0.500  1.0
  Al  Al35  1  0.976  0.476  0.858  1.0
  Al  Al36  1  0.118  0.976  0.500  1.0
  Al  Al37  1  0.524  0.382  0.500  1.0
  Si  Si38  1  0.750  0.750  1.000  1.0
  Si  Si39  1  0.250  0.250  1.000  1.0
[/CIF]
.