data_C3Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.15
_cell_length_b   5.15
_cell_length_c   5.15
_cell_angle_alpha   148.08
_cell_angle_beta   98.67
_cell_angle_gamma   90.03
_symmetry_Int_Tables_number   1
_chemical_formula_structural   C3Se
_chemical_formula_sum   'C3 Se1'
_cell_volume   69.04
_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
  C  C0  1  0.0  0.29  0.0  1.0
  C  C1  1  0.0  0.42  0.0  1.0
  C  C2  1  0.0  0.0  0.0  1.0
  Se  Se3  1  0.0  0.35  0.0  1.0

data_C3Se
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.83
_cell_length_b   5.15
_cell_length_c   5.15
_cell_angle_alpha   81.33
_cell_angle_beta   74.04
_cell_angle_gamma   74.04
_symmetry_Int_Tables_number   1
_chemical_formula_structural   C3Se
_chemical_formula_sum   'C3 Se1'
_cell_volume   69.04
_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
  C  C0  1  0.0  0.0  0.0  1.0
  C  C1  1  0.29  0.0  0.71  1.0
  Se  Se2  1  0.35  0.0  0.65  1.0
  C  C3  1  0.42  0.0  0.58  1.0

C C C Se
C3Se is Cyanogen Chloride-derived structured and crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one C3Se cluster. There are three inequivalent C sites. In the first C site, C(1) is bonded in a linear geometry to one C(3) and one Se(1) atom. The C(1)-C(3) bond length is 1.49 Å. The C(1)-Se(1) bond length is 0.33 Å. In the second C site, C(2) is bonded in a single-bond geometry to one Se(1) atom. The C(2)-Se(1) bond length is 0.33 Å. In the third C site, C(3) is bonded in a single-bond geometry to one C(1) atom. Se(1) is bonded in a linear geometry to one C(1) and one C(2) atom.