The material described by ErTb3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. Er(1) is bonded to four equivalent Tb(2) and eight equivalent Tb(1) atoms to form ErTb12 cuboctahedra that share corners with four equivalent Er(1)Tb12 cuboctahedra, corners with eight equivalent Tb(2)Tb8Er4 cuboctahedra, edges with eight equivalent Er(1)Tb12 cuboctahedra, edges with sixteen equivalent Tb(1)Tb8Er4 cuboctahedra, faces with four equivalent Er(1)Tb12 cuboctahedra, faces with six equivalent Tb(2)Tb8Er4 cuboctahedra, and faces with eight equivalent Tb(1)Tb8Er4 cuboctahedra. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded to four equivalent Er(1), four equivalent Tb(1), and four equivalent Tb(2) atoms to form TbTb8Er4 cuboctahedra that share corners with twelve equivalent Tb(1)Tb8Er4 cuboctahedra, edges with eight equivalent Er(1)Tb12 cuboctahedra, edges with eight equivalent Tb(1)Tb8Er4 cuboctahedra, edges with eight equivalent Tb(2)Tb8Er4 cuboctahedra, faces with four equivalent Er(1)Tb12 cuboctahedra, faces with four equivalent Tb(2)Tb8Er4 cuboctahedra, and faces with ten equivalent Tb(1)Tb8Er4 cuboctahedra. In the second Tb site, Tb(2) is bonded to four equivalent Er(1) and eight equivalent Tb(1) atoms to form TbTb8Er4 cuboctahedra that share corners with four equivalent Tb(2)Tb8Er4 cuboctahedra, corners with eight equivalent Er(1)Tb12 cuboctahedra, edges with eight equivalent Tb(2)Tb8Er4 cuboctahedra, edges with sixteen equivalent Tb(1)Tb8Er4 cuboctahedra, faces with four equivalent Tb(2)Tb8Er4 cuboctahedra, faces with six equivalent Er(1)Tb12 cuboctahedra, and faces with eight equivalent Tb(1)Tb8Er4 cuboctahedra. is represented by the CIF card [CIF]
data_Tb3Er
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.159
_cell_length_b   6.159
_cell_length_c   6.159
_cell_angle_alpha   131.958
_cell_angle_beta   131.958
_cell_angle_gamma   70.295
_symmetry_Int_Tables_number   1
_cell_volume   126.593
_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  0.750  0.250  0.500  1.0
  Tb  Tb1  1  0.250  0.750  0.500  1.0
  Tb  Tb2  1  0.500  0.500  0.000  1.0
  Er  Er3  1  0.000  0.000  0.000  1.0
[/CIF]
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The material described by ErTb3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. Er(1) is bonded to four equivalent Tb(2) and eight equivalent Tb(1) atoms to form ErTb12 cuboctahedra that share corners with four equivalent Er(1)Tb12 cuboctahedra, corners with eight equivalent Tb(2)Tb8Er4 cuboctahedra, edges with eight equivalent Er(1)Tb12 cuboctahedra, edges with sixteen equivalent Tb(1)Tb8Er4 cuboctahedra, faces with four equivalent Er(1)Tb12 cuboctahedra, faces with six equivalent Tb(2)Tb8Er4 cuboctahedra, and faces with eight equivalent Tb(1)Tb8Er4 cuboctahedra. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded to four equivalent Er(1), four equivalent Tb(1), and four equivalent Tb(2) atoms to form TbTb8Er4 cuboctahedra that share corners with twelve equivalent Tb(1)Tb8Er4 cuboctahedra, edges with eight equivalent Er(1)Tb12 cuboctahedra, edges with eight equivalent Tb(1)Tb8Er4 cuboctahedra, edges with eight equivalent Tb(2)Tb8Er4 cuboctahedra, faces with four equivalent Er(1)Tb12 cuboctahedra, faces with four equivalent Tb(2)Tb8Er4 cuboctahedra, and faces with ten equivalent Tb(1)Tb8Er4 cuboctahedra. In the second Tb site, Tb(2) is bonded to four equivalent Er(1) and eight equivalent Tb(1) atoms to form TbTb8Er4 cuboctahedra that share corners with four equivalent Tb(2)Tb8Er4 cuboctahedra, corners with eight equivalent Er(1)Tb12 cuboctahedra, edges with eight equivalent Tb(2)Tb8Er4 cuboctahedra, edges with sixteen equivalent Tb(1)Tb8Er4 cuboctahedra, faces with four equivalent Tb(2)Tb8Er4 cuboctahedra, faces with six equivalent Er(1)Tb12 cuboctahedra, and faces with eight equivalent Tb(1)Tb8Er4 cuboctahedra. is represented by the CIF card [CIF]
data_Tb3Er
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.159
_cell_length_b   6.159
_cell_length_c   6.159
_cell_angle_alpha   131.958
_cell_angle_beta   131.958
_cell_angle_gamma   70.295
_symmetry_Int_Tables_number   1
_cell_volume   126.593
_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  0.750  0.250  0.500  1.0
  Tb  Tb1  1  0.250  0.750  0.500  1.0
  Tb  Tb2  1  0.500  0.500  0.000  1.0
  Er  Er3  1  0.000  0.000  0.000  1.0
[/CIF]
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