data_SiBSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.23
_cell_length_b   6.23
_cell_length_c   6.23
_cell_angle_alpha   33.33
_cell_angle_beta   33.33
_cell_angle_gamma   33.33
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SiBSe2
_chemical_formula_sum   'Si1 B1 Se2'
_cell_volume   64.89
_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
  Si  Si3  1  0.0  0.0  0.81  1.0
  B  B0  1  0.0  0.0  0.0  1.0
  Se  Se1  1  0.0  0.0  0.09  1.0
  Se  Se2  1  0.0  0.0  0.54  1.0

data_SiBSe2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.19
_cell_length_b   3.57
_cell_length_c   6.23
_cell_angle_alpha   90.0
_cell_angle_beta   109.34
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   SiBSe2
_chemical_formula_sum   'Si2 B2 Se4'
_cell_volume   129.77
_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
  Si  Si0  2  -0.0  0.0  0.19  1.0
  B  B1  2  -0.0  0.0  0.0  1.0
  Se  Se2  2  -0.0  0.0  0.46  1.0
  Se  Se3  2  -0.0  0.0  0.91  1.0

Si B Se Se
BSiSe2 is Indium-like structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two BSiSe2 clusters. B(1) is bonded in a linear geometry to one Si(1) and one Se(1) atom. The B(1)-Si(1) bond length is 1.17 Å. The B(1)-Se(1) bond length is 0.55 Å. Si(1) is bonded in a linear geometry to one B(1) and one Se(2) atom. The Si(1)-Se(2) bond length is 1.72 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a single-bond geometry to one B(1) atom. In the second Se site, Se(2) is bonded in a single-bond geometry to one Si(1) atom.