data_Ba2AlBr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.89
_cell_length_b   4.89
_cell_length_c   6.92
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ba2AlBr
_chemical_formula_sum   'Ba2 Al1 Br1'
_cell_volume   165.37
_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
  Ba  Ba1  1  0.44  0.44  0.0  1.0
  Ba  Ba2  1  0.0  0.0  0.46  1.0
  Al  Al0  1  0.0  0.0  0.0  1.0
  Br  Br3  1  0.44  0.44  0.46  1.0

data_Ba2AlBr
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.91
_cell_length_b   6.91
_cell_length_c   6.92
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Ba2AlBr
_chemical_formula_sum   'Ba4 Al2 Br2'
_cell_volume   330.74
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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
  Ba  Ba0  2  0.0  0.0  0.46  1.0
  Ba  Ba1  2  0.44  0.0  0.0  1.0
  Al  Al2  2  0.0  0.0  0.0  1.0
  Br  Br3  2  0.44  0.0  0.46  1.0

Ba Ba Al Br
Ba Ba Al Br 0 2 o o o 0 2 o + o 0 2 + o o 0 2 + + o 0 3 o o - 0 3 o o o 1 3 - - o 1 3 - o o 1 3 o - o 1 3 o o o 1 2 o o o 1 2 o o + 
Ba2AlBr is High Pressure (4-7GPa) Tellurium-derived structured and crystallizes in the monoclinic Cm space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to four equivalent Al(1) and two equivalent Br(1) atoms to form distorted BaAl4Br2 octahedra that share corners with six equivalent Ba(1)Al4Br2 octahedra, edges with four equivalent Ba(1)Al4Br2 octahedra, and edges with eight equivalent Ba(2)Al2Br4 octahedra. The corner-sharing octahedral tilt angles range from 0-13°. There are a spread of Ba(1)-Al(1) bond distances ranging from 3.07-3.85 Å. There is one shorter (3.20 Å) and one longer (3.73 Å) Ba(1)-Br(1) bond length. In the second Ba site, Ba(2) is bonded to two equivalent Al(1) and four equivalent Br(1) atoms to form distorted BaAl2Br4 octahedra that share corners with six equivalent Ba(2)Al2Br4 octahedra, edges with four equivalent Ba(2)Al2Br4 octahedra, and edges with eight equivalent Ba(1)Al4Br2 octahedra. The corner-sharing octahedral tilt angles range from 0-13°. There is one shorter (3.20 Å) and one longer (3.73 Å) Ba(2)-Al(1) bond length. There are a spread of Ba(2)-Br(1) bond distances ranging from 3.07-3.85 Å. Al(1) is bonded to two equivalent Ba(2) and four equivalent Ba(1) atoms to form AlBa6 octahedra that share corners with six equivalent Al(1)Ba6 octahedra, edges with four equivalent Al(1)Ba6 octahedra, and edges with eight equivalent Br(1)Ba6 octahedra. The corner-sharing octahedral tilt angles range from 0-13°. Br(1) is bonded to two equivalent Ba(1) and four equivalent Ba(2) atoms to form BrBa6 octahedra that share corners with six equivalent Br(1)Ba6 octahedra, edges with four equivalent Br(1)Ba6 octahedra, and edges with eight equivalent Al(1)Ba6 octahedra. The corner-sharing octahedral tilt angles range from 0-13°.