The material structure described by Tb3Si2S8I crystallizes in the monoclinic C2/c space group. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 9-coordinate geometry to one S(3), two equivalent S(2), two equivalent S(4), three equivalent S(1), and one I(1) atom. In the second Tb site, Tb(2) is bonded in a 9-coordinate geometry to two equivalent S(2), two equivalent S(4), four equivalent S(3), and one I(1) atom. Si(1) is bonded in a tetrahedral geometry to one S(1), one S(2), one S(3), and one S(4) atom. There are four inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to three equivalent Tb(1) and one Si(1) atom. In the second S site, S(2) is bonded to one Tb(2), two equivalent Tb(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing STb3Si trigonal pyramids. In the third S site, S(3) is bonded in a 4-coordinate geometry to one Tb(1), two equivalent Tb(2), and one Si(1) atom. In the fourth S site, S(4) is bonded to one Tb(2), two equivalent Tb(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing STb3Si trigonal pyramids. I(1) is bonded in a 3-coordinate geometry to one Tb(2) and two equivalent Tb(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Tb3Si2S8I
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.772
_cell_length_b   8.772
_cell_length_c   10.695
_cell_angle_alpha   81.840
_cell_angle_beta   81.840
_cell_angle_gamma   51.957
_symmetry_Int_Tables_number   1
_cell_volume   639.965
_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
  Tb  Tb0  1  0.328  0.076  0.319  1.0
  Tb  Tb1  1  0.924  0.672  0.181  1.0
  Tb  Tb2  1  0.672  0.924  0.681  1.0
  Tb  Tb3  1  0.612  0.388  0.250  1.0
  Tb  Tb4  1  0.076  0.328  0.819  1.0
  Tb  Tb5  1  0.388  0.612  0.750  1.0
  Si  Si6  1  0.620  0.696  0.975  1.0
  Si  Si7  1  0.696  0.620  0.475  1.0
  Si  Si8  1  0.304  0.380  0.525  1.0
  Si  Si9  1  0.380  0.304  0.025  1.0
  S  S10  1  0.149  0.285  0.087  1.0
  S  S11  1  0.550  0.745  0.170  1.0
  S  S12  1  0.715  0.851  0.413  1.0
  S  S13  1  0.255  0.450  0.330  1.0
  S  S14  1  0.450  0.255  0.830  1.0
  S  S15  1  0.269  0.595  0.035  1.0
  S  S16  1  0.745  0.550  0.670  1.0
  S  S17  1  0.895  0.392  0.354  1.0
  S  S18  1  0.392  0.895  0.854  1.0
  S  S19  1  0.405  0.731  0.465  1.0
  S  S20  1  0.595  0.269  0.535  1.0
  S  S21  1  0.851  0.715  0.913  1.0
  S  S22  1  0.608  0.105  0.146  1.0
  S  S23  1  0.285  0.149  0.587  1.0
  S  S24  1  0.731  0.405  0.965  1.0
  S  S25  1  0.105  0.608  0.646  1.0
  I  I26  1  0.018  0.982  0.250  1.0
  I  I27  1  0.982  0.018  0.750  1.0
[/CIF]
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The material structure described by Tb3Si2S8I crystallizes in the monoclinic C2/c space group. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 9-coordinate geometry to one S(3), two equivalent S(2), two equivalent S(4), three equivalent S(1), and one I(1) atom. In the second Tb site, Tb(2) is bonded in a 9-coordinate geometry to two equivalent S(2), two equivalent S(4), four equivalent S(3), and one I(1) atom. Si(1) is bonded in a tetrahedral geometry to one S(1), one S(2), one S(3), and one S(4) atom. There are four inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to three equivalent Tb(1) and one Si(1) atom. In the second S site, S(2) is bonded to one Tb(2), two equivalent Tb(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing STb3Si trigonal pyramids. In the third S site, S(3) is bonded in a 4-coordinate geometry to one Tb(1), two equivalent Tb(2), and one Si(1) atom. In the fourth S site, S(4) is bonded to one Tb(2), two equivalent Tb(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing STb3Si trigonal pyramids. I(1) is bonded in a 3-coordinate geometry to one Tb(2) and two equivalent Tb(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Tb3Si2S8I
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.772
_cell_length_b   8.772
_cell_length_c   10.695
_cell_angle_alpha   81.840
_cell_angle_beta   81.840
_cell_angle_gamma   51.957
_symmetry_Int_Tables_number   1
_cell_volume   639.965
_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
  Tb  Tb0  1  0.328  0.076  0.319  1.0
  Tb  Tb1  1  0.924  0.672  0.181  1.0
  Tb  Tb2  1  0.672  0.924  0.681  1.0
  Tb  Tb3  1  0.612  0.388  0.250  1.0
  Tb  Tb4  1  0.076  0.328  0.819  1.0
  Tb  Tb5  1  0.388  0.612  0.750  1.0
  Si  Si6  1  0.620  0.696  0.975  1.0
  Si  Si7  1  0.696  0.620  0.475  1.0
  Si  Si8  1  0.304  0.380  0.525  1.0
  Si  Si9  1  0.380  0.304  0.025  1.0
  S  S10  1  0.149  0.285  0.087  1.0
  S  S11  1  0.550  0.745  0.170  1.0
  S  S12  1  0.715  0.851  0.413  1.0
  S  S13  1  0.255  0.450  0.330  1.0
  S  S14  1  0.450  0.255  0.830  1.0
  S  S15  1  0.269  0.595  0.035  1.0
  S  S16  1  0.745  0.550  0.670  1.0
  S  S17  1  0.895  0.392  0.354  1.0
  S  S18  1  0.392  0.895  0.854  1.0
  S  S19  1  0.405  0.731  0.465  1.0
  S  S20  1  0.595  0.269  0.535  1.0
  S  S21  1  0.851  0.715  0.913  1.0
  S  S22  1  0.608  0.105  0.146  1.0
  S  S23  1  0.285  0.149  0.587  1.0
  S  S24  1  0.731  0.405  0.965  1.0
  S  S25  1  0.105  0.608  0.646  1.0
  I  I26  1  0.018  0.982  0.250  1.0
  I  I27  1  0.982  0.018  0.750  1.0
[/CIF]
.