The material described by Al2Si2Sr crystallizes in the trigonal P-3m1 space group. Sr(1) is bonded to six equivalent Si(1) atoms to form distorted SrSi6 octahedra that share corners with twelve equivalent Al(1)Si4 tetrahedra, edges with six equivalent Sr(1)Si6 octahedra, and edges with six equivalent Al(1)Si4 tetrahedra. Al(1) is bonded to four equivalent Si(1) atoms to form AlSi4 tetrahedra that share corners with six equivalent Sr(1)Si6 octahedra, corners with six equivalent Al(1)Si4 tetrahedra, edges with three equivalent Sr(1)Si6 octahedra, and edges with three equivalent Al(1)Si4 tetrahedra. The corner-sharing octahedral tilt angles range from 24-49°. Si(1) is bonded in a 7-coordinate geometry to three equivalent Sr(1) and four equivalent Al(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sr(AlSi)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.190
_cell_length_b   4.190
_cell_length_c   7.439
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   113.127
_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
  Sr  Sr0  1  0.000  0.000  0.000  1.0
  Al  Al1  1  0.667  0.333  0.376  1.0
  Al  Al2  1  0.333  0.667  0.624  1.0
  Si  Si3  1  0.667  0.333  0.722  1.0
  Si  Si4  1  0.333  0.667  0.278  1.0
[/CIF]
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The material described by Al2Si2Sr crystallizes in the trigonal P-3m1 space group. Sr(1) is bonded to six equivalent Si(1) atoms to form distorted SrSi6 octahedra that share corners with twelve equivalent Al(1)Si4 tetrahedra, edges with six equivalent Sr(1)Si6 octahedra, and edges with six equivalent Al(1)Si4 tetrahedra. Al(1) is bonded to four equivalent Si(1) atoms to form AlSi4 tetrahedra that share corners with six equivalent Sr(1)Si6 octahedra, corners with six equivalent Al(1)Si4 tetrahedra, edges with three equivalent Sr(1)Si6 octahedra, and edges with three equivalent Al(1)Si4 tetrahedra. The corner-sharing octahedral tilt angles range from 24-49°. Si(1) is bonded in a 7-coordinate geometry to three equivalent Sr(1) and four equivalent Al(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sr(AlSi)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.190
_cell_length_b   4.190
_cell_length_c   7.439
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   113.127
_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
  Sr  Sr0  1  0.000  0.000  0.000  1.0
  Al  Al1  1  0.667  0.333  0.376  1.0
  Al  Al2  1  0.333  0.667  0.624  1.0
  Si  Si3  1  0.667  0.333  0.722  1.0
  Si  Si4  1  0.333  0.667  0.278  1.0
[/CIF]
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