The material described by Tb2Fe17 crystallizes in the trigonal R-3m space group. Tb(1) is bonded in a 19-coordinate geometry to one Fe(1), three equivalent Fe(4), six equivalent Fe(3), and nine equivalent Fe(2) atoms. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 14-coordinate geometry to one Tb(1), one Fe(1), three equivalent Fe(2), three equivalent Fe(4), and six equivalent Fe(3) atoms. In the second Fe site, Fe(2) is bonded to three equivalent Tb(1), one Fe(1), two equivalent Fe(2), two equivalent Fe(4), and four equivalent Fe(3) atoms to form FeTb3Fe9 cuboctahedra that share corners with five equivalent Fe(4)Tb2Fe10 cuboctahedra, corners with ten equivalent Fe(2)Tb3Fe9 cuboctahedra, edges with three equivalent Fe(4)Tb2Fe10 cuboctahedra, edges with five equivalent Fe(2)Tb3Fe9 cuboctahedra, faces with three equivalent Fe(4)Tb2Fe10 cuboctahedra, and faces with seven equivalent Fe(2)Tb3Fe9 cuboctahedra. In the third Fe site, Fe(3) is bonded in a 12-coordinate geometry to two equivalent Tb(1), two equivalent Fe(1), two equivalent Fe(3), two equivalent Fe(4), and four equivalent Fe(2) atoms. In the fourth Fe site, Fe(4) is bonded to two equivalent Tb(1), two equivalent Fe(1), four equivalent Fe(2), and four equivalent Fe(3) atoms to form FeTb2Fe10 cuboctahedra that share corners with four equivalent Fe(4)Tb2Fe10 cuboctahedra, corners with ten equivalent Fe(2)Tb3Fe9 cuboctahedra, edges with six equivalent Fe(2)Tb3Fe9 cuboctahedra, faces with four equivalent Fe(4)Tb2Fe10 cuboctahedra, and faces with six equivalent Fe(2)Tb3Fe9 cuboctahedra. is represented by the CIF file [CIF]
data_Tb2Fe17
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.426
_cell_length_b   6.426
_cell_length_c   6.426
_cell_angle_alpha   83.393
_cell_angle_beta   83.392
_cell_angle_gamma   83.393
_symmetry_Int_Tables_number   1
_cell_volume   260.488
_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
  Tb  Tb0  1  0.661  0.661  0.661  1.0
  Tb  Tb1  1  0.339  0.339  0.339  1.0
  Fe  Fe2  1  0.096  0.096  0.096  1.0
  Fe  Fe3  1  0.656  0.154  0.656  1.0
  Fe  Fe4  1  0.904  0.904  0.904  1.0
  Fe  Fe5  1  0.707  0.000  0.293  1.0
  Fe  Fe6  1  0.707  0.293  0.000  1.0
  Fe  Fe7  1  0.000  0.707  0.293  1.0
  Fe  Fe8  1  0.293  1.000  0.707  1.0
  Fe  Fe9  1  0.344  0.344  0.846  1.0
  Fe  Fe10  1  0.000  0.293  0.707  1.0
  Fe  Fe11  1  0.000  1.000  0.500  1.0
  Fe  Fe12  1  0.656  0.656  0.154  1.0
  Fe  Fe13  1  0.344  0.846  0.344  1.0
  Fe  Fe14  1  0.846  0.344  0.344  1.0
  Fe  Fe15  1  0.000  0.500  0.000  1.0
  Fe  Fe16  1  0.293  0.707  1.000  1.0
  Fe  Fe17  1  0.500  1.000  0.000  1.0
  Fe  Fe18  1  0.154  0.656  0.656  1.0
[/CIF]
.
The material described by Tb2Fe17 crystallizes in the trigonal R-3m space group. Tb(1) is bonded in a 19-coordinate geometry to one Fe(1), three equivalent Fe(4), six equivalent Fe(3), and nine equivalent Fe(2) atoms. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 14-coordinate geometry to one Tb(1), one Fe(1), three equivalent Fe(2), three equivalent Fe(4), and six equivalent Fe(3) atoms. In the second Fe site, Fe(2) is bonded to three equivalent Tb(1), one Fe(1), two equivalent Fe(2), two equivalent Fe(4), and four equivalent Fe(3) atoms to form FeTb3Fe9 cuboctahedra that share corners with five equivalent Fe(4)Tb2Fe10 cuboctahedra, corners with ten equivalent Fe(2)Tb3Fe9 cuboctahedra, edges with three equivalent Fe(4)Tb2Fe10 cuboctahedra, edges with five equivalent Fe(2)Tb3Fe9 cuboctahedra, faces with three equivalent Fe(4)Tb2Fe10 cuboctahedra, and faces with seven equivalent Fe(2)Tb3Fe9 cuboctahedra. In the third Fe site, Fe(3) is bonded in a 12-coordinate geometry to two equivalent Tb(1), two equivalent Fe(1), two equivalent Fe(3), two equivalent Fe(4), and four equivalent Fe(2) atoms. In the fourth Fe site, Fe(4) is bonded to two equivalent Tb(1), two equivalent Fe(1), four equivalent Fe(2), and four equivalent Fe(3) atoms to form FeTb2Fe10 cuboctahedra that share corners with four equivalent Fe(4)Tb2Fe10 cuboctahedra, corners with ten equivalent Fe(2)Tb3Fe9 cuboctahedra, edges with six equivalent Fe(2)Tb3Fe9 cuboctahedra, faces with four equivalent Fe(4)Tb2Fe10 cuboctahedra, and faces with six equivalent Fe(2)Tb3Fe9 cuboctahedra. is represented by the CIF file [CIF]
data_Tb2Fe17
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.426
_cell_length_b   6.426
_cell_length_c   6.426
_cell_angle_alpha   83.393
_cell_angle_beta   83.392
_cell_angle_gamma   83.393
_symmetry_Int_Tables_number   1
_cell_volume   260.488
_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
  Tb  Tb0  1  0.661  0.661  0.661  1.0
  Tb  Tb1  1  0.339  0.339  0.339  1.0
  Fe  Fe2  1  0.096  0.096  0.096  1.0
  Fe  Fe3  1  0.656  0.154  0.656  1.0
  Fe  Fe4  1  0.904  0.904  0.904  1.0
  Fe  Fe5  1  0.707  0.000  0.293  1.0
  Fe  Fe6  1  0.707  0.293  0.000  1.0
  Fe  Fe7  1  0.000  0.707  0.293  1.0
  Fe  Fe8  1  0.293  1.000  0.707  1.0
  Fe  Fe9  1  0.344  0.344  0.846  1.0
  Fe  Fe10  1  0.000  0.293  0.707  1.0
  Fe  Fe11  1  0.000  1.000  0.500  1.0
  Fe  Fe12  1  0.656  0.656  0.154  1.0
  Fe  Fe13  1  0.344  0.846  0.344  1.0
  Fe  Fe14  1  0.846  0.344  0.344  1.0
  Fe  Fe15  1  0.000  0.500  0.000  1.0
  Fe  Fe16  1  0.293  0.707  1.000  1.0
  Fe  Fe17  1  0.500  1.000  0.000  1.0
  Fe  Fe18  1  0.154  0.656  0.656  1.0
[/CIF]
.