data_C2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.82
_cell_length_b   4.33
_cell_length_c   8.58
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   C2Se
_chemical_formula_sum   'C8 Se4'
_cell_volume   253.49
_cell_formula_units_Z   4
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  0.38  0.08  0.29  1.0
  C  C1  1  0.03  0.25  0.0  1.0
  C  C2  1  0.79  0.08  0.58  1.0
  C  C3  1  0.44  0.25  0.29  1.0
  C  C4  1  0.51  0.08  0.39  1.0
  C  C5  1  0.72  0.25  0.1  1.0
  C  C6  1  0.1  0.08  0.48  1.0
  C  C7  1  0.31  0.25  0.19  1.0
  Se  Se8  1  0.8  0.08  0.26  1.0
  Se  Se9  1  0.61  0.25  0.55  1.0
  Se  Se10  1  0.21  0.08  0.04  1.0
  Se  Se11  1  0.02  0.25  0.33  1.0

data_C2Se
_symmetry_space_group_name_H-M   P-1
_cell_length_a   4.33
_cell_length_b   6.82
_cell_length_c   8.58
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   C2Se
_chemical_formula_sum   'C8 Se4'
_cell_volume   253.49
_cell_formula_units_Z   4
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
  C  C0  2  0.42  0.19  0.69  1.0
  Se  Se1  2  0.42  0.3  0.24  1.0
  C  C2  2  0.42  0.47  0.5  1.0
  C  C3  2  0.42  0.6  0.6  1.0
  C  C4  2  0.42  0.88  0.79  1.0
  Se  Se5  2  0.42  0.89  0.46  1.0

C C C C C C C C Se Se Se Se
C C C C C C C C Se Se Se Se 0 3 o o o 0 4 o o o 0 7 o o o 1 10 o o o 2 9 o o o 3 4 o o o 3 7 o o o 4 9 o o o 5 8 o o o 6 11 o o o 7 10 o o o 8 11 + o o 