data_Si5Se3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.32
_cell_length_b   5.04
_cell_length_c   8.77
_cell_angle_alpha   90.0
_cell_angle_beta   114.91
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si5Se3
_chemical_formula_sum   'Si10 Se6'
_cell_volume   333.35
_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
  Si  Si6  1  0.3  0.78  0.67  1.0
  Si  Si7  1  0.29  0.26  0.34  1.0
  Si  Si8  1  0.29  0.78  0.34  1.0
  Si  Si9  1  0.3  0.26  0.67  1.0
  Si  Si10  1  0.72  0.52  0.23  1.0
  Si  Si11  1  0.93  0.0  0.7  1.0
  Si  Si12  1  0.1  0.52  0.88  1.0
  Si  Si13  1  0.11  0.52  0.65  1.0
  Si  Si14  1  0.45  0.0  0.51  1.0
  Si  Si15  1  0.32  0.0  0.05  1.0
  Se  Se0  1  0.92  0.52  0.15  1.0
  Se  Se1  1  0.72  0.0  0.79  1.0
  Se  Se2  1  0.29  0.52  0.87  1.0
  Se  Se3  1  0.88  0.52  0.58  1.0
  Se  Se4  1  0.84  0.0  0.17  1.0
  Se  Se5  1  0.55  0.0  0.04  1.0

data_Si5Se3
_symmetry_space_group_name_H-M   P1
_cell_length_a   5.04
_cell_length_b   8.32
_cell_length_c   8.77
_cell_angle_alpha   114.91
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si5Se3
_chemical_formula_sum   'Si10 Se6'
_cell_volume   333.35
_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
  Si  Si0  1  0.0  0.07  0.3  1.0
  Si  Si1  1  0.0  0.55  0.49  1.0
  Si  Si2  1  0.0  0.68  0.95  1.0
  Si  Si3  1  0.22  0.71  0.66  1.0
  Si  Si4  1  0.22  0.7  0.33  1.0
  Si  Si5  1  0.48  0.28  0.77  1.0
  Si  Si6  1  0.48  0.89  0.35  1.0
  Si  Si7  1  0.48  0.9  0.12  1.0
  Si  Si8  1  0.74  0.7  0.33  1.0
  Si  Si9  1  0.74  0.71  0.66  1.0
  Se  Se10  1  0.0  0.16  0.83  1.0
  Se  Se11  1  0.0  0.28  0.21  1.0
  Se  Se12  1  0.0  0.45  0.96  1.0
  Se  Se13  1  0.48  0.08  0.85  1.0
  Se  Se14  1  0.48  0.12  0.42  1.0
  Se  Se15  1  0.48  0.71  0.13  1.0

Si Si Si Si Si Si Si Si Si Si Se Se Se Se Se Se
Si5Se3 crystallizes in the triclinic P1 space group. There are ten inequivalent Si sites. In the first Si site, Si(1) is bonded in a 1-coordinate geometry to one Si(3), one Si(9), and one Se(3) atom. The Si(1)-Si(3) bond length is 2.79 Å. The Si(1)-Si(9) bond length is 2.46 Å. The Si(1)-Se(3) bond length is 2.22 Å. In the second Si site, Si(2) is bonded in a 6-coordinate geometry to one Si(10), one Si(4), one Si(9), two equivalent Si(3), and one Se(1) atom. The Si(2)-Si(10) bond length is 2.97 Å. The Si(2)-Si(4) bond length is 2.79 Å. The Si(2)-Si(9) bond length is 1.99 Å. There is one shorter (2.40 Å) and one longer (2.63 Å) Si(2)-Si(3) bond length. The Si(2)-Se(1) bond length is 3.12 Å. In the third Si site, Si(3) is bonded in a 6-coordinate geometry to one Si(1), one Si(10), one Si(9), two equivalent Si(2), and one Se(1) atom. The Si(3)-Si(10) bond length is 2.89 Å. The Si(3)-Si(9) bond length is 1.87 Å. The Si(3)-Se(1) bond length is 3.12 Å. In the fourth Si site, Si(4) is bonded in a 1-coordinate geometry to one Si(2), one Si(9), and one Se(3) atom. The Si(4)-Si(9) bond length is 2.55 Å. The Si(4)-Se(3) bond length is 2.22 Å. In the fifth Si site, Si(5) is bonded in a 1-coordinate geometry to one Se(1) and two equivalent Se(5) atoms. The Si(5)-Se(1) bond length is 2.04 Å. There is one shorter (2.73 Å) and one longer (2.90 Å) Si(5)-Se(5) bond length. In the sixth Si site, Si(6) is bonded in a 3-coordinate geometry to one Se(2) and two equivalent Se(4) atoms. The Si(6)-Se(2) bond length is 2.16 Å. There is one shorter (2.62 Å) and one longer (2.80 Å) Si(6)-Se(4) bond length. In the seventh Si site, Si(7) is bonded in a single-bond geometry to one Se(3) atom. The Si(7)-Se(3) bond length is 1.67 Å. In the eighth Si site, Si(8) is bonded in a 2-coordinate geometry to one Se(3) and one Se(4) atom. The Si(8)-Se(3) bond length is 1.85 Å. The Si(8)-Se(4) bond length is 1.76 Å. In the ninth Si site, Si(9) is bonded in a 5-coordinate geometry to one Si(1), one Si(2), one Si(3), one Si(4), and one Se(2) atom. The Si(9)-Se(2) bond length is 2.56 Å. In the tenth Si site, Si(10) is bonded in a distorted single-bond geometry to one Si(2), one Si(3), and one Se(6) atom. The Si(10)-Se(6) bond length is 1.96 Å. There are six inequivalent Se sites. In the first Se site, Se(1) is bonded in a single-bond geometry to one Si(2), one Si(3), one Si(5), and two equivalent Se(5) atoms. There is one shorter (2.55 Å) and one longer (2.73 Å) Se(1)-Se(5) bond length. In the second Se site, Se(2) is bonded in a distorted water-like geometry to one Si(6), one Si(9), and one Se(5) atom. The Se(2)-Se(5) bond length is 3.07 Å. In the third Se site, Se(3) is bonded in a 2-coordinate geometry to one Si(1), one Si(4), one Si(7), and one Si(8) atom. In the fourth Se site, Se(4) is bonded in a 1-coordinate geometry to one Si(8) and two equivalent Si(6) atoms. In the fifth Se site, Se(5) is bonded in a 6-coordinate geometry to two equivalent Si(5), one Se(2), one Se(6), and two equivalent Se(1) atoms. The Se(5)-Se(6) bond length is 2.18 Å. In the sixth Se site, Se(6) is bonded in a distorted single-bond geometry to one Si(10) and one Se(5) atom.