data_BaHfSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.9
_cell_length_b   7.9
_cell_length_c   7.9
_cell_angle_alpha   29.44
_cell_angle_beta   29.44
_cell_angle_gamma   29.44
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BaHfSe2
_chemical_formula_sum   'Ba1 Hf1 Se2'
_cell_volume   105.31
_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  0.0  0.36  1.0
  Hf  Hf1  1  0.0  0.0  0.38  1.0
  Se  Se2  1  0.0  0.0  0.07  1.0
  Se  Se3  1  0.0  0.0  0.49  1.0

data_BaHfSe2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.95
_cell_length_b   4.01
_cell_length_c   7.9
_cell_angle_alpha   90.0
_cell_angle_beta   107.06
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   BaHfSe2
_chemical_formula_sum   'Ba2 Hf2 Se4'
_cell_volume   210.61
_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  0.64  1.0
  Hf  Hf1  2  0.0  0.0  0.62  1.0
  Se  Se2  2  0.0  0.0  0.51  1.0
  Se  Se3  2  0.0  0.0  0.93  1.0

Ba Hf Se Se
Ba Hf Se Se 0 1 o o o 0 2 o o o 0 3 o o o 1 2 o o o 1 3 o o o 
BaHfSe2 is Cyanogen Chloride-like structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two BaHfSe2 clusters. Ba(1) is bonded in a distorted linear geometry to one Hf(1) and one Se(1) atom. The Ba(1)-Hf(1) bond length is 0.14 Å. The Ba(1)-Se(1) bond length is 2.27 Å. Hf(1) is bonded in a linear geometry to one Ba(1) and one Se(2) atom. The Hf(1)-Se(2) bond length is 0.90 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a single-bond geometry to one Ba(1) atom. In the second Se site, Se(2) is bonded in a single-bond geometry to one Hf(1) atom.