The crystal structure described by K3AlBr6 crystallizes in the cubic Fm-3m space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to twelve equivalent Br(1) atoms to form distorted KBr12 cuboctahedra that share corners with twelve equivalent K(1)Br12 cuboctahedra, faces with six equivalent K(1)Br12 cuboctahedra, faces with four equivalent K(2)Br6 octahedra, and faces with four equivalent Al(1)Br6 octahedra. In the second K site, K(2) is bonded to six equivalent Br(1) atoms to form KBr6 octahedra that share corners with six equivalent Al(1)Br6 octahedra and faces with eight equivalent K(1)Br12 cuboctahedra. The corner-sharing octahedra are not tilted. Al(1) is bonded to six equivalent Br(1) atoms to form AlBr6 octahedra that share corners with six equivalent K(2)Br6 octahedra and faces with eight equivalent K(1)Br12 cuboctahedra. The corner-sharing octahedra are not tilted. Br(1) is bonded in a linear geometry to one K(2), four equivalent K(1), and one Al(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_K3AlBr6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.965
_cell_length_b   7.965
_cell_length_c   7.965
_cell_angle_alpha   60.000
_cell_angle_beta   60.000
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   357.342
_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
  K  K0  1  0.750  0.750  0.750  1.0
  K  K1  1  0.250  0.250  0.250  1.0
  K  K2  1  0.500  0.500  0.500  1.0
  Al  Al3  1  0.000  0.000  0.000  1.0
  Br  Br4  1  0.776  0.224  0.224  1.0
  Br  Br5  1  0.224  0.224  0.776  1.0
  Br  Br6  1  0.224  0.776  0.776  1.0
  Br  Br7  1  0.224  0.776  0.224  1.0
  Br  Br8  1  0.776  0.224  0.776  1.0
  Br  Br9  1  0.776  0.776  0.224  1.0
[/CIF]
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The crystal structure described by K3AlBr6 crystallizes in the cubic Fm-3m space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to twelve equivalent Br(1) atoms to form distorted KBr12 cuboctahedra that share corners with twelve equivalent K(1)Br12 cuboctahedra, faces with six equivalent K(1)Br12 cuboctahedra, faces with four equivalent K(2)Br6 octahedra, and faces with four equivalent Al(1)Br6 octahedra. In the second K site, K(2) is bonded to six equivalent Br(1) atoms to form KBr6 octahedra that share corners with six equivalent Al(1)Br6 octahedra and faces with eight equivalent K(1)Br12 cuboctahedra. The corner-sharing octahedra are not tilted. Al(1) is bonded to six equivalent Br(1) atoms to form AlBr6 octahedra that share corners with six equivalent K(2)Br6 octahedra and faces with eight equivalent K(1)Br12 cuboctahedra. The corner-sharing octahedra are not tilted. Br(1) is bonded in a linear geometry to one K(2), four equivalent K(1), and one Al(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_K3AlBr6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.965
_cell_length_b   7.965
_cell_length_c   7.965
_cell_angle_alpha   60.000
_cell_angle_beta   60.000
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   357.342
_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
  K  K0  1  0.750  0.750  0.750  1.0
  K  K1  1  0.250  0.250  0.250  1.0
  K  K2  1  0.500  0.500  0.500  1.0
  Al  Al3  1  0.000  0.000  0.000  1.0
  Br  Br4  1  0.776  0.224  0.224  1.0
  Br  Br5  1  0.224  0.224  0.776  1.0
  Br  Br6  1  0.224  0.776  0.776  1.0
  Br  Br7  1  0.224  0.776  0.224  1.0
  Br  Br8  1  0.776  0.224  0.776  1.0
  Br  Br9  1  0.776  0.776  0.224  1.0
[/CIF]
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