The structure described by BeTbCu4 crystallizes in the hexagonal P-6m2 space group. Be(1) is bonded in a 12-coordinate geometry to three equivalent Tb(1), three equivalent Cu(1), and six equivalent Cu(2) atoms. Tb(1) is bonded in a 18-coordinate geometry to three equivalent Be(1), three equivalent Cu(1), and twelve equivalent Cu(2) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to three equivalent Be(1), three equivalent Tb(1), and six equivalent Cu(2) atoms to form distorted CuTb3Be3Cu6 cuboctahedra that share corners with twelve equivalent Cu(2)Tb4Be2Cu6 cuboctahedra, edges with six equivalent Cu(1)Tb3Be3Cu6 cuboctahedra, faces with two equivalent Cu(1)Tb3Be3Cu6 cuboctahedra, and faces with eighteen equivalent Cu(2)Tb4Be2Cu6 cuboctahedra. In the second Cu site, Cu(2) is bonded to two equivalent Be(1), four equivalent Tb(1), two equivalent Cu(1), and four equivalent Cu(2) atoms to form distorted CuTb4Be2Cu6 cuboctahedra that share corners with four equivalent Cu(1)Tb3Be3Cu6 cuboctahedra, corners with sixteen equivalent Cu(2)Tb4Be2Cu6 cuboctahedra, edges with ten equivalent Cu(2)Tb4Be2Cu6 cuboctahedra, faces with six equivalent Cu(1)Tb3Be3Cu6 cuboctahedra, and faces with ten equivalent Cu(2)Tb4Be2Cu6 cuboctahedra. is represented by the CIF file [CIF]
data_TbBeCu4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.071
_cell_length_b   5.071
_cell_length_c   3.872
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   86.234
_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  0.333  0.667  0.000  1.0
  Be  Be1  1  0.667  0.333  0.000  1.0
  Cu  Cu2  1  0.000  0.000  0.000  1.0
  Cu  Cu3  1  0.342  0.171  0.500  1.0
  Cu  Cu4  1  0.829  0.171  0.500  1.0
  Cu  Cu5  1  0.829  0.658  0.500  1.0
[/CIF]
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The structure described by BeTbCu4 crystallizes in the hexagonal P-6m2 space group. Be(1) is bonded in a 12-coordinate geometry to three equivalent Tb(1), three equivalent Cu(1), and six equivalent Cu(2) atoms. Tb(1) is bonded in a 18-coordinate geometry to three equivalent Be(1), three equivalent Cu(1), and twelve equivalent Cu(2) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to three equivalent Be(1), three equivalent Tb(1), and six equivalent Cu(2) atoms to form distorted CuTb3Be3Cu6 cuboctahedra that share corners with twelve equivalent Cu(2)Tb4Be2Cu6 cuboctahedra, edges with six equivalent Cu(1)Tb3Be3Cu6 cuboctahedra, faces with two equivalent Cu(1)Tb3Be3Cu6 cuboctahedra, and faces with eighteen equivalent Cu(2)Tb4Be2Cu6 cuboctahedra. In the second Cu site, Cu(2) is bonded to two equivalent Be(1), four equivalent Tb(1), two equivalent Cu(1), and four equivalent Cu(2) atoms to form distorted CuTb4Be2Cu6 cuboctahedra that share corners with four equivalent Cu(1)Tb3Be3Cu6 cuboctahedra, corners with sixteen equivalent Cu(2)Tb4Be2Cu6 cuboctahedra, edges with ten equivalent Cu(2)Tb4Be2Cu6 cuboctahedra, faces with six equivalent Cu(1)Tb3Be3Cu6 cuboctahedra, and faces with ten equivalent Cu(2)Tb4Be2Cu6 cuboctahedra. is represented by the CIF file [CIF]
data_TbBeCu4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.071
_cell_length_b   5.071
_cell_length_c   3.872
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   86.234
_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  0.333  0.667  0.000  1.0
  Be  Be1  1  0.667  0.333  0.000  1.0
  Cu  Cu2  1  0.000  0.000  0.000  1.0
  Cu  Cu3  1  0.342  0.171  0.500  1.0
  Cu  Cu4  1  0.829  0.171  0.500  1.0
  Cu  Cu5  1  0.829  0.658  0.500  1.0
[/CIF]
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