The material structure described by Tb2Se3 is Stibnite structured and crystallizes in the orthorhombic Pnma space group. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded to two equivalent Se(1), two equivalent Se(2), and three equivalent Se(3) atoms to form a mixture of distorted edge and corner-sharing TbSe7 pentagonal bipyramids. In the second Tb site, Tb(2) is bonded in a 8-coordinate geometry to two equivalent Se(3), three equivalent Se(1), and three equivalent Se(2) atoms. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a 5-coordinate geometry to two equivalent Tb(1) and three equivalent Tb(2) atoms. In the second Se site, Se(2) is bonded to two equivalent Tb(1) and three equivalent Tb(2) atoms to form a mixture of distorted edge and corner-sharing SeTb5 trigonal bipyramids. In the third Se site, Se(3) is bonded to two equivalent Tb(2) and three equivalent Tb(1) atoms to form a mixture of edge and corner-sharing SeTb5 square pyramids. is represented by the CIF file [CIF]
data_Tb2Se3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.033
_cell_length_b   11.007
_cell_length_c   11.152
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   495.129
_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
  Tb  Tb0  1  0.250  0.187  0.488  1.0
  Tb  Tb1  1  0.750  0.813  0.512  1.0
  Tb  Tb2  1  0.750  0.687  0.012  1.0
  Tb  Tb3  1  0.250  0.313  0.988  1.0
  Tb  Tb4  1  0.250  0.998  0.807  1.0
  Tb  Tb5  1  0.750  0.002  0.193  1.0
  Tb  Tb6  1  0.750  0.498  0.693  1.0
  Tb  Tb7  1  0.250  0.502  0.307  1.0
  Se  Se8  1  0.250  0.305  0.726  1.0
  Se  Se9  1  0.750  0.695  0.274  1.0
  Se  Se10  1  0.750  0.805  0.774  1.0
  Se  Se11  1  0.250  0.195  0.226  1.0
  Se  Se12  1  0.250  0.626  0.545  1.0
  Se  Se13  1  0.750  0.374  0.455  1.0
  Se  Se14  1  0.750  0.126  0.955  1.0
  Se  Se15  1  0.250  0.874  0.045  1.0
  Se  Se16  1  0.250  0.556  0.881  1.0
  Se  Se17  1  0.750  0.444  0.119  1.0
  Se  Se18  1  0.750  0.056  0.619  1.0
  Se  Se19  1  0.250  0.944  0.381  1.0
[/CIF]
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The material structure described by Tb2Se3 is Stibnite structured and crystallizes in the orthorhombic Pnma space group. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded to two equivalent Se(1), two equivalent Se(2), and three equivalent Se(3) atoms to form a mixture of distorted edge and corner-sharing TbSe7 pentagonal bipyramids. In the second Tb site, Tb(2) is bonded in a 8-coordinate geometry to two equivalent Se(3), three equivalent Se(1), and three equivalent Se(2) atoms. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a 5-coordinate geometry to two equivalent Tb(1) and three equivalent Tb(2) atoms. In the second Se site, Se(2) is bonded to two equivalent Tb(1) and three equivalent Tb(2) atoms to form a mixture of distorted edge and corner-sharing SeTb5 trigonal bipyramids. In the third Se site, Se(3) is bonded to two equivalent Tb(2) and three equivalent Tb(1) atoms to form a mixture of edge and corner-sharing SeTb5 square pyramids. is represented by the CIF file [CIF]
data_Tb2Se3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.033
_cell_length_b   11.007
_cell_length_c   11.152
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   495.129
_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
  Tb  Tb0  1  0.250  0.187  0.488  1.0
  Tb  Tb1  1  0.750  0.813  0.512  1.0
  Tb  Tb2  1  0.750  0.687  0.012  1.0
  Tb  Tb3  1  0.250  0.313  0.988  1.0
  Tb  Tb4  1  0.250  0.998  0.807  1.0
  Tb  Tb5  1  0.750  0.002  0.193  1.0
  Tb  Tb6  1  0.750  0.498  0.693  1.0
  Tb  Tb7  1  0.250  0.502  0.307  1.0
  Se  Se8  1  0.250  0.305  0.726  1.0
  Se  Se9  1  0.750  0.695  0.274  1.0
  Se  Se10  1  0.750  0.805  0.774  1.0
  Se  Se11  1  0.250  0.195  0.226  1.0
  Se  Se12  1  0.250  0.626  0.545  1.0
  Se  Se13  1  0.750  0.374  0.455  1.0
  Se  Se14  1  0.750  0.126  0.955  1.0
  Se  Se15  1  0.250  0.874  0.045  1.0
  Se  Se16  1  0.250  0.556  0.881  1.0
  Se  Se17  1  0.750  0.444  0.119  1.0
  Se  Se18  1  0.750  0.056  0.619  1.0
  Se  Se19  1  0.250  0.944  0.381  1.0
[/CIF]
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