The material described by YbCu4Al crystallizes in the hexagonal P-6m2 space group. Yb(1) is bonded in a 18-coordinate geometry to three equivalent Cu(1), twelve equivalent Cu(2), and three equivalent Al(1) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to three equivalent Yb(1), six equivalent Cu(2), and three equivalent Al(1) atoms to form CuYb3Al3Cu6 cuboctahedra that share corners with nine equivalent Al(1)Yb3Cu9 cuboctahedra, corners with twelve equivalent Cu(2)Yb4Al2Cu6 cuboctahedra, edges with six equivalent Cu(1)Yb3Al3Cu6 cuboctahedra, faces with two equivalent Cu(1)Yb3Al3Cu6 cuboctahedra, faces with three equivalent Al(1)Yb3Cu9 cuboctahedra, and faces with eighteen equivalent Cu(2)Yb4Al2Cu6 cuboctahedra. In the second Cu site, Cu(2) is bonded to four equivalent Yb(1), two equivalent Cu(1), four equivalent Cu(2), and two equivalent Al(1) atoms to form distorted CuYb4Al2Cu6 cuboctahedra that share corners with four equivalent Cu(1)Yb3Al3Cu6 cuboctahedra, corners with four equivalent Al(1)Yb3Cu9 cuboctahedra, corners with sixteen equivalent Cu(2)Yb4Al2Cu6 cuboctahedra, edges with ten equivalent Cu(2)Yb4Al2Cu6 cuboctahedra, faces with six equivalent Cu(1)Yb3Al3Cu6 cuboctahedra, faces with six equivalent Al(1)Yb3Cu9 cuboctahedra, and faces with ten equivalent Cu(2)Yb4Al2Cu6 cuboctahedra. Al(1) is bonded to three equivalent Yb(1), three equivalent Cu(1), and six equivalent Cu(2) atoms to form distorted AlYb3Cu9 cuboctahedra that share corners with nine equivalent Cu(1)Yb3Al3Cu6 cuboctahedra, corners with twelve equivalent Cu(2)Yb4Al2Cu6 cuboctahedra, edges with six equivalent Al(1)Yb3Cu9 cuboctahedra, faces with two equivalent Al(1)Yb3Cu9 cuboctahedra, faces with three equivalent Cu(1)Yb3Al3Cu6 cuboctahedra, and faces with eighteen equivalent Cu(2)Yb4Al2Cu6 cuboctahedra. is represented by the CIF card [CIF]
data_YbAlCu4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.145
_cell_length_b   5.145
_cell_length_c   4.032
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   92.437
_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
  Yb  Yb0  1  0.000  0.000  0.000  1.0
  Al  Al1  1  0.333  0.667  0.000  1.0
  Cu  Cu2  1  0.667  0.333  0.000  1.0
  Cu  Cu3  1  0.998  0.499  0.500  1.0
  Cu  Cu4  1  0.501  0.499  0.500  1.0
  Cu  Cu5  1  0.501  0.002  0.500  1.0
[/CIF]
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The material described by YbCu4Al crystallizes in the hexagonal P-6m2 space group. Yb(1) is bonded in a 18-coordinate geometry to three equivalent Cu(1), twelve equivalent Cu(2), and three equivalent Al(1) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to three equivalent Yb(1), six equivalent Cu(2), and three equivalent Al(1) atoms to form CuYb3Al3Cu6 cuboctahedra that share corners with nine equivalent Al(1)Yb3Cu9 cuboctahedra, corners with twelve equivalent Cu(2)Yb4Al2Cu6 cuboctahedra, edges with six equivalent Cu(1)Yb3Al3Cu6 cuboctahedra, faces with two equivalent Cu(1)Yb3Al3Cu6 cuboctahedra, faces with three equivalent Al(1)Yb3Cu9 cuboctahedra, and faces with eighteen equivalent Cu(2)Yb4Al2Cu6 cuboctahedra. In the second Cu site, Cu(2) is bonded to four equivalent Yb(1), two equivalent Cu(1), four equivalent Cu(2), and two equivalent Al(1) atoms to form distorted CuYb4Al2Cu6 cuboctahedra that share corners with four equivalent Cu(1)Yb3Al3Cu6 cuboctahedra, corners with four equivalent Al(1)Yb3Cu9 cuboctahedra, corners with sixteen equivalent Cu(2)Yb4Al2Cu6 cuboctahedra, edges with ten equivalent Cu(2)Yb4Al2Cu6 cuboctahedra, faces with six equivalent Cu(1)Yb3Al3Cu6 cuboctahedra, faces with six equivalent Al(1)Yb3Cu9 cuboctahedra, and faces with ten equivalent Cu(2)Yb4Al2Cu6 cuboctahedra. Al(1) is bonded to three equivalent Yb(1), three equivalent Cu(1), and six equivalent Cu(2) atoms to form distorted AlYb3Cu9 cuboctahedra that share corners with nine equivalent Cu(1)Yb3Al3Cu6 cuboctahedra, corners with twelve equivalent Cu(2)Yb4Al2Cu6 cuboctahedra, edges with six equivalent Al(1)Yb3Cu9 cuboctahedra, faces with two equivalent Al(1)Yb3Cu9 cuboctahedra, faces with three equivalent Cu(1)Yb3Al3Cu6 cuboctahedra, and faces with eighteen equivalent Cu(2)Yb4Al2Cu6 cuboctahedra. is represented by the CIF card [CIF]
data_YbAlCu4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.145
_cell_length_b   5.145
_cell_length_c   4.032
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   92.437
_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
  Yb  Yb0  1  0.000  0.000  0.000  1.0
  Al  Al1  1  0.333  0.667  0.000  1.0
  Cu  Cu2  1  0.667  0.333  0.000  1.0
  Cu  Cu3  1  0.998  0.499  0.500  1.0
  Cu  Cu4  1  0.501  0.499  0.500  1.0
  Cu  Cu5  1  0.501  0.002  0.500  1.0
[/CIF]
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