data_Ba2BiSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.81
_cell_length_b   6.97
_cell_length_c   4.99
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ba2BiSe
_chemical_formula_sum   'Ba2 Bi1 Se1'
_cell_volume   167.04
_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  Ba0  1  0.0  0.49  0.65  1.0
  Ba  Ba1  1  0.4  0.0  0.09  1.0
  Bi  Bi2  1  0.4  0.49  0.15  1.0
  Se  Se3  1  0.0  0.0  0.6  1.0

data_Ba2BiSe
_symmetry_space_group_name_H-M   P1
_cell_length_a   4.81
_cell_length_b   4.99
_cell_length_c   6.97
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ba2BiSe
_chemical_formula_sum   'Ba2 Bi1 Se1'
_cell_volume   167.04
_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  Ba0  1  0.0  0.35  0.51  1.0
  Ba  Ba1  1  0.6  0.91  0.0  1.0
  Bi  Bi2  1  0.6  0.85  0.51  1.0
  Se  Se3  1  0.0  0.4  0.0  1.0

Ba Ba Bi Se
Ba2BiSe is Caswellsilverite-like structured and crystallizes in the triclinic P1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to four equivalent Bi(1) and two equivalent Se(1) atoms to form BaBi4Se2 octahedra that share corners with six equivalent Ba(1)Bi4Se2 octahedra, edges with four equivalent Ba(1)Bi4Se2 octahedra, and edges with eight equivalent Ba(2)Bi2Se4 octahedra. The corner-sharing octahedral tilt angles range from 7-11°. There are a spread of Ba(1)-Bi(1) bond distances ranging from 3.15-3.80 Å. There is one shorter (3.39 Å) and one longer (3.59 Å) Ba(1)-Se(1) bond length. In the second Ba site, Ba(2) is bonded to two equivalent Bi(1) and four equivalent Se(1) atoms to form distorted BaBi2Se4 octahedra that share corners with six equivalent Ba(2)Bi2Se4 octahedra, edges with four equivalent Ba(2)Bi2Se4 octahedra, and edges with eight equivalent Ba(1)Bi4Se2 octahedra. The corner-sharing octahedral tilt angles range from 9-13°. There is one shorter (3.40 Å) and one longer (3.60 Å) Ba(2)-Bi(1) bond length. There are a spread of Ba(2)-Se(1) bond distances ranging from 3.10-3.85 Å. Bi(1) is bonded to two equivalent Ba(2) and four equivalent Ba(1) atoms to form BiBa6 octahedra that share corners with six equivalent Bi(1)Ba6 octahedra, edges with four equivalent Bi(1)Ba6 octahedra, and edges with eight equivalent Se(1)Ba6 octahedra. The corner-sharing octahedral tilt angles range from 10-11°. Se(1) is bonded to two equivalent Ba(1) and four equivalent Ba(2) atoms to form SeBa6 octahedra that share corners with six equivalent Se(1)Ba6 octahedra, edges with four equivalent Se(1)Ba6 octahedra, and edges with eight equivalent Bi(1)Ba6 octahedra. The corner-sharing octahedral tilt angles range from 7-13°.