data_BaAlSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.54
_cell_length_b   7.54
_cell_length_c   7.54
_cell_angle_alpha   150.87
_cell_angle_beta   147.86
_cell_angle_gamma   43.92
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BaAlSe2
_chemical_formula_sum   'Ba1 Al1 Se2'
_cell_volume   110.8
_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  0.0  0.09  0.8  1.0
  Al  Al0  1  0.0  0.0  0.44  1.0
  Se  Se2  1  0.0  0.0  0.29  1.0
  Se  Se3  1  0.9  0.0  0.46  1.0

data_BaAlSe2
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.79
_cell_length_b   4.18
_cell_length_c   7.54
_cell_angle_alpha   106.07
_cell_angle_beta   104.56
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BaAlSe2
_chemical_formula_sum   'Ba1 Al1 Se2'
_cell_volume   110.8
_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  0.91  0.72  0.72  1.0
  Al  Al1  1  0.0  0.44  0.44  1.0
  Se  Se2  1  0.0  0.29  0.29  1.0
  Se  Se3  1  0.0  0.46  0.57  1.0

Ba Al Se Se
BaAlSe2 crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one BaAlSe2 cluster. Ba(1) is bonded in a single-bond geometry to one Se(2) atom. The Ba(1)-Se(2) bond length is 1.42 Å. Al(1) is bonded in a bent 150 degrees geometry to one Se(1) and one Se(2) atom. The Al(1)-Se(1) bond length is 1.15 Å. The Al(1)-Se(2) bond length is 0.94 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a single-bond geometry to one Al(1) atom. In the second Se site, Se(2) is bonded in a distorted bent 150 degrees geometry to one Ba(1) and one Al(1) atom.