The material described by ErAuAl4Ge2 crystallizes in the trigonal R-3m space group. Er(1) is bonded to six equivalent Ge(1) atoms to form ErGe6 octahedra that share corners with six equivalent Al(1)Ge3Au tetrahedra, corners with six equivalent Al(2)GeAu3 tetrahedra, edges with six equivalent Er(1)Ge6 octahedra, and edges with six equivalent Al(1)Ge3Au tetrahedra. Au(1) is bonded in a body-centered cubic geometry to two equivalent Al(1) and six equivalent Al(2) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one Au(1) and three equivalent Ge(1) atoms to form AlGe3Au tetrahedra that share corners with three equivalent Er(1)Ge6 octahedra, corners with three equivalent Al(2)GeAu3 tetrahedra, corners with seven equivalent Al(1)Ge3Au tetrahedra, edges with three equivalent Er(1)Ge6 octahedra, and edges with three equivalent Al(2)GeAu3 tetrahedra. The corner-sharing octahedral tilt angles are 15°. In the second Al site, Al(2) is bonded to three equivalent Au(1) and one Ge(1) atom to form distorted AlGeAu3 tetrahedra that share corners with three equivalent Er(1)Ge6 octahedra, corners with three equivalent Al(1)Ge3Au tetrahedra, corners with nine equivalent Al(2)GeAu3 tetrahedra, edges with three equivalent Al(1)Ge3Au tetrahedra, and edges with three equivalent Al(2)GeAu3 tetrahedra. The corner-sharing octahedral tilt angles are 56°. Ge(1) is bonded to three equivalent Er(1), one Al(2), and three equivalent Al(1) atoms to form a mixture of distorted edge and corner-sharing GeEr3Al4 pentagonal bipyramids. is represented by the CIF card [CIF]
data_ErAl4Ge2Au
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.560
_cell_length_b   10.560
_cell_length_c   10.560
_cell_angle_alpha   23.173
_cell_angle_beta   23.173
_cell_angle_gamma   23.173
_symmetry_Int_Tables_number   1
_cell_volume   160.079
_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
  Er  Er0  1  0.500  0.500  0.500  1.0
  Al  Al1  1  0.916  0.916  0.916  1.0
  Al  Al2  1  0.693  0.693  0.693  1.0
  Al  Al3  1  0.084  0.084  0.084  1.0
  Al  Al4  1  0.307  0.307  0.307  1.0
  Ge  Ge5  1  0.779  0.779  0.779  1.0
  Ge  Ge6  1  0.221  0.221  0.221  1.0
  Au  Au7  1  0.000  0.000  0.000  1.0
[/CIF]
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The material described by ErAuAl4Ge2 crystallizes in the trigonal R-3m space group. Er(1) is bonded to six equivalent Ge(1) atoms to form ErGe6 octahedra that share corners with six equivalent Al(1)Ge3Au tetrahedra, corners with six equivalent Al(2)GeAu3 tetrahedra, edges with six equivalent Er(1)Ge6 octahedra, and edges with six equivalent Al(1)Ge3Au tetrahedra. Au(1) is bonded in a body-centered cubic geometry to two equivalent Al(1) and six equivalent Al(2) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one Au(1) and three equivalent Ge(1) atoms to form AlGe3Au tetrahedra that share corners with three equivalent Er(1)Ge6 octahedra, corners with three equivalent Al(2)GeAu3 tetrahedra, corners with seven equivalent Al(1)Ge3Au tetrahedra, edges with three equivalent Er(1)Ge6 octahedra, and edges with three equivalent Al(2)GeAu3 tetrahedra. The corner-sharing octahedral tilt angles are 15°. In the second Al site, Al(2) is bonded to three equivalent Au(1) and one Ge(1) atom to form distorted AlGeAu3 tetrahedra that share corners with three equivalent Er(1)Ge6 octahedra, corners with three equivalent Al(1)Ge3Au tetrahedra, corners with nine equivalent Al(2)GeAu3 tetrahedra, edges with three equivalent Al(1)Ge3Au tetrahedra, and edges with three equivalent Al(2)GeAu3 tetrahedra. The corner-sharing octahedral tilt angles are 56°. Ge(1) is bonded to three equivalent Er(1), one Al(2), and three equivalent Al(1) atoms to form a mixture of distorted edge and corner-sharing GeEr3Al4 pentagonal bipyramids. is represented by the CIF card [CIF]
data_ErAl4Ge2Au
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.560
_cell_length_b   10.560
_cell_length_c   10.560
_cell_angle_alpha   23.173
_cell_angle_beta   23.173
_cell_angle_gamma   23.173
_symmetry_Int_Tables_number   1
_cell_volume   160.079
_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
  Er  Er0  1  0.500  0.500  0.500  1.0
  Al  Al1  1  0.916  0.916  0.916  1.0
  Al  Al2  1  0.693  0.693  0.693  1.0
  Al  Al3  1  0.084  0.084  0.084  1.0
  Al  Al4  1  0.307  0.307  0.307  1.0
  Ge  Ge5  1  0.779  0.779  0.779  1.0
  Ge  Ge6  1  0.221  0.221  0.221  1.0
  Au  Au7  1  0.000  0.000  0.000  1.0
[/CIF]
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