data_Ba2TiSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.09
_cell_length_b   7.09
_cell_length_c   7.09
_cell_angle_alpha   140.78
_cell_angle_beta   140.78
_cell_angle_gamma   56.67
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ba2TiSe
_chemical_formula_sum   'Ba2 Ti1 Se1'
_cell_volume   141.35
_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  0.38  0.12  1.0
  Ba  Ba1  1  0.0  0.0  0.24  1.0
  Ti  Ti3  1  0.0  0.0  0.0  1.0
  Se  Se2  1  0.38  0.0  0.12  1.0

data_Ba2TiSe
_symmetry_space_group_name_H-M   P1
_cell_length_a   4.76
_cell_length_b   4.76
_cell_length_c   7.09
_cell_angle_alpha   109.61
_cell_angle_beta   109.61
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ba2TiSe
_chemical_formula_sum   'Ba2 Ti1 Se1'
_cell_volume   141.35
_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  0.26  0.38  0.26  1.0
  Ba  Ba1  1  0.76  0.0  0.76  1.0
  Ti  Ti2  1  0.0  0.0  0.0  1.0
  Se  Se3  1  0.88  0.0  0.26  1.0

Ba Ba Ti Se
Ba2TiSe crystallizes in the triclinic P1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 4-coordinate geometry to one Ti(1) and three equivalent Se(1) atoms. The Ba(1)-Ti(1) bond length is 2.10 Å. There is one shorter (2.55 Å) and two longer (3.46 Å) Ba(1)-Se(1) bond lengths. In the second Ba site, Ba(2) is bonded in a distorted single-bond geometry to one Ti(1) and one Se(1) atom. The Ba(2)-Ti(1) bond length is 1.71 Å. The Ba(2)-Se(1) bond length is 3.78 Å. Ti(1) is bonded in a 3-coordinate geometry to one Ba(1), one Ba(2), and one Se(1) atom. The Ti(1)-Se(1) bond length is 2.10 Å. Se(1) is bonded in a 5-coordinate geometry to one Ba(2), three equivalent Ba(1), and one Ti(1) atom.