The crystal structure described by Tb4Si7 crystallizes in the monoclinic C2/m space group. There are three inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 9-coordinate geometry to two equivalent Si(1), two equivalent Si(2), two equivalent Si(3), and three equivalent Si(5) atoms. In the second Tb site, Tb(2) is bonded to one Si(2), one Si(3), four equivalent Si(1), and six equivalent Si(4) atoms to form a mixture of distorted face and edge-sharing TbSi12 cuboctahedra. In the third Tb site, Tb(3) is bonded to one Si(2), one Si(3), four equivalent Si(1), and six equivalent Si(4) atoms to form a mixture of distorted face and edge-sharing TbSi12 cuboctahedra. There are five inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Tb(1), two equivalent Tb(2), two equivalent Tb(3), one Si(2), one Si(3), and one Si(4) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to one Tb(2), one Tb(3), four equivalent Tb(1), one Si(5), and two equivalent Si(1) atoms. In the third Si site, Si(3) is bonded in a 8-coordinate geometry to one Tb(2), one Tb(3), four equivalent Tb(1), and two equivalent Si(1) atoms. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to three equivalent Tb(2), three equivalent Tb(3), one Si(1), and two equivalent Si(4) atoms. In the fifth Si site, Si(5) is bonded in a 8-coordinate geometry to six equivalent Tb(1), one Si(2), and one Si(5) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Tb4Si7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.716
_cell_length_b   5.716
_cell_length_c   13.558
_cell_angle_alpha   89.123
_cell_angle_beta   89.123
_cell_angle_gamma   88.654
_symmetry_Int_Tables_number   1
_cell_volume   442.785
_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  0.887  0.380  0.128  1.0
  Tb  Tb1  1  0.620  0.113  0.872  1.0
  Tb  Tb2  1  0.873  0.873  0.627  1.0
  Tb  Tb3  1  0.127  0.127  0.373  1.0
  Tb  Tb4  1  0.380  0.887  0.128  1.0
  Tb  Tb5  1  0.113  0.620  0.872  1.0
  Tb  Tb6  1  0.373  0.373  0.627  1.0
  Tb  Tb7  1  0.627  0.627  0.373  1.0
  Si  Si8  1  0.861  0.383  0.713  1.0
  Si  Si9  1  0.617  0.139  0.287  1.0
  Si  Si10  1  0.882  0.882  0.208  1.0
  Si  Si11  1  0.118  0.118  0.792  1.0
  Si  Si12  1  0.383  0.861  0.713  1.0
  Si  Si13  1  0.139  0.617  0.287  1.0
  Si  Si14  1  0.384  0.384  0.182  1.0
  Si  Si15  1  0.616  0.616  0.818  1.0
  Si  Si16  1  0.875  0.372  0.541  1.0
  Si  Si17  1  0.628  0.125  0.459  1.0
  Si  Si18  1  0.862  0.862  0.035  1.0
  Si  Si19  1  0.138  0.138  0.965  1.0
  Si  Si20  1  0.372  0.875  0.541  1.0
  Si  Si21  1  0.125  0.628  0.459  1.0
[/CIF]
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The crystal structure described by Tb4Si7 crystallizes in the monoclinic C2/m space group. There are three inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 9-coordinate geometry to two equivalent Si(1), two equivalent Si(2), two equivalent Si(3), and three equivalent Si(5) atoms. In the second Tb site, Tb(2) is bonded to one Si(2), one Si(3), four equivalent Si(1), and six equivalent Si(4) atoms to form a mixture of distorted face and edge-sharing TbSi12 cuboctahedra. In the third Tb site, Tb(3) is bonded to one Si(2), one Si(3), four equivalent Si(1), and six equivalent Si(4) atoms to form a mixture of distorted face and edge-sharing TbSi12 cuboctahedra. There are five inequivalent Si sites. In the first Si site, Si(1) is bonded in a 9-coordinate geometry to two equivalent Tb(1), two equivalent Tb(2), two equivalent Tb(3), one Si(2), one Si(3), and one Si(4) atom. In the second Si site, Si(2) is bonded in a 9-coordinate geometry to one Tb(2), one Tb(3), four equivalent Tb(1), one Si(5), and two equivalent Si(1) atoms. In the third Si site, Si(3) is bonded in a 8-coordinate geometry to one Tb(2), one Tb(3), four equivalent Tb(1), and two equivalent Si(1) atoms. In the fourth Si site, Si(4) is bonded in a 9-coordinate geometry to three equivalent Tb(2), three equivalent Tb(3), one Si(1), and two equivalent Si(4) atoms. In the fifth Si site, Si(5) is bonded in a 8-coordinate geometry to six equivalent Tb(1), one Si(2), and one Si(5) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Tb4Si7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.716
_cell_length_b   5.716
_cell_length_c   13.558
_cell_angle_alpha   89.123
_cell_angle_beta   89.123
_cell_angle_gamma   88.654
_symmetry_Int_Tables_number   1
_cell_volume   442.785
_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  0.887  0.380  0.128  1.0
  Tb  Tb1  1  0.620  0.113  0.872  1.0
  Tb  Tb2  1  0.873  0.873  0.627  1.0
  Tb  Tb3  1  0.127  0.127  0.373  1.0
  Tb  Tb4  1  0.380  0.887  0.128  1.0
  Tb  Tb5  1  0.113  0.620  0.872  1.0
  Tb  Tb6  1  0.373  0.373  0.627  1.0
  Tb  Tb7  1  0.627  0.627  0.373  1.0
  Si  Si8  1  0.861  0.383  0.713  1.0
  Si  Si9  1  0.617  0.139  0.287  1.0
  Si  Si10  1  0.882  0.882  0.208  1.0
  Si  Si11  1  0.118  0.118  0.792  1.0
  Si  Si12  1  0.383  0.861  0.713  1.0
  Si  Si13  1  0.139  0.617  0.287  1.0
  Si  Si14  1  0.384  0.384  0.182  1.0
  Si  Si15  1  0.616  0.616  0.818  1.0
  Si  Si16  1  0.875  0.372  0.541  1.0
  Si  Si17  1  0.628  0.125  0.459  1.0
  Si  Si18  1  0.862  0.862  0.035  1.0
  Si  Si19  1  0.138  0.138  0.965  1.0
  Si  Si20  1  0.372  0.875  0.541  1.0
  Si  Si21  1  0.125  0.628  0.459  1.0
[/CIF]
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