data_SrAl2Br
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.27
_cell_length_b   5.27
_cell_length_c   5.27
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SrAl2Br
_chemical_formula_sum   'Sr1 Al2 Br1'
_cell_volume   103.55
_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  Sr3  1  0.59  0.59  0.59  1.0
  Al  Al0  1  0.0  0.0  0.0  1.0
  Al  Al1  1  0.86  0.86  0.86  1.0
  Br  Br2  1  0.73  0.73  0.73  1.0

data_SrAl2Br
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.27
_cell_length_b   5.27
_cell_length_c   12.91
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   SrAl2Br
_chemical_formula_sum   'Sr3 Al6 Br3'
_cell_volume   310.64
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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  3  0.0  0.0  0.41  1.0
  Al  Al1  3  0.0  0.0  0.0  1.0
  Al  Al2  3  0.0  0.0  0.14  1.0
  Br  Br3  3  0.0  0.0  0.27  1.0

Sr Al Al Br
Sr Al Al Br 0 3 o o o 1 2 - - - 2 3 o o o 
SrAl2Br crystallizes in the trigonal R3m space group. Sr(1) is bonded in a single-bond geometry to three equivalent Al(1) and one Br(1) atom. All Sr(1)-Al(1) bond lengths are 3.20 Å. The Sr(1)-Br(1) bond length is 1.76 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a distorted single-bond geometry to three equivalent Sr(1), one Al(2), and three equivalent Br(1) atoms. The Al(1)-Al(2) bond length is 1.76 Å. All Al(1)-Br(1) bond lengths are 3.14 Å. In the second Al site, Al(2) is bonded in a distorted single-bond geometry to one Al(1) and one Br(1) atom. The Al(2)-Br(1) bond length is 1.76 Å. Br(1) is bonded in a linear geometry to one Sr(1), one Al(2), and three equivalent Al(1) atoms.