data_YbSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.0
_cell_length_b   5.0
_cell_length_c   5.87
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   YbSe
_chemical_formula_sum   'Yb2 Se2'
_cell_volume   127.33
_cell_formula_units_Z   2
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
  Yb  Yb0  1  0.0  0.89  0.4  1.0
  Yb  Yb1  1  0.5  0.44  0.47  1.0
  Se  Se2  1  0.0  0.89  0.47  1.0
  Se  Se3  1  0.5  0.44  0.4  1.0

data_YbSe
_symmetry_space_group_name_H-M   P-1
_cell_length_a   5.0
_cell_length_b   5.0
_cell_length_c   5.87
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   YbSe
_chemical_formula_sum   'Yb2 Se2'
_cell_volume   127.33
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-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
  Yb  Yb0  2  0.25  0.28  0.03  1.0
  Se  Se1  2  0.25  0.28  0.97  1.0

Yb Yb Se Se
YbSe is alpha carbon monoxide-like structured and crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of two YbSe clusters. Yb(1) is bonded in a single-bond geometry to one Se(1) atom. The Yb(1)-Se(1) bond length is 0.38 Å. Se(1) is bonded in a single-bond geometry to one Yb(1) atom.