data_BaSn2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.79
_cell_length_b   5.79
_cell_length_c   5.79
_cell_angle_alpha   126.77
_cell_angle_beta   126.77
_cell_angle_gamma   78.63
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BaSn2Se
_chemical_formula_sum   'Ba1 Sn2 Se1'
_cell_volume   120.77
_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  0.6  0.24  1.0
  Sn  Sn2  1  0.6  0.0  0.24  1.0
  Sn  Sn3  1  0.0  0.0  0.48  1.0
  Se  Se1  1  0.0  0.0  0.0  1.0

data_BaSn2Se
_symmetry_space_group_name_H-M   P1
_cell_length_a   5.19
_cell_length_b   5.19
_cell_length_c   5.79
_cell_angle_alpha   116.62
_cell_angle_beta   116.62
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BaSn2Se
_chemical_formula_sum   'Ba1 Sn2 Se1'
_cell_volume   120.77
_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  0.65  0.24  0.65  1.0
  Sn  Sn1  1  0.24  0.65  0.65  1.0
  Sn  Sn2  1  0.48  0.48  0.48  1.0
  Se  Se3  1  0.0  0.0  0.0  1.0

Ba Sn Sn Se
BaSn2Se crystallizes in the triclinic P1 space group. Ba(1) is bonded in a 2-coordinate geometry to one Sn(2) and three equivalent Se(1) atoms. The Ba(1)-Sn(2) bond length is 1.88 Å. There are a spread of Ba(1)-Se(1) bond distances ranging from 2.84-3.53 Å. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a distorted linear geometry to one Sn(2) and one Se(1) atom. The Sn(1)-Sn(2) bond length is 1.88 Å. The Sn(1)-Se(1) bond length is 2.84 Å. In the second Sn site, Sn(2) is bonded in a distorted single-bond geometry to one Ba(1), one Sn(1), and two equivalent Se(1) atoms. There is one shorter (2.79 Å) and one longer (3.00 Å) Sn(2)-Se(1) bond length. Se(1) is bonded in a 6-coordinate geometry to three equivalent Ba(1), one Sn(1), and two equivalent Sn(2) atoms.