The structure described by Cu3TaSe4 is Sulvanite structured and crystallizes in the cubic P-43m space group. Ta(1) is bonded to six equivalent Cu(1) and four equivalent Se(1) atoms to form distorted TaCu6Se4 tetrahedra that share corners with six equivalent Ta(1)Cu6Se4 tetrahedra, corners with twelve equivalent Se(1)TaCu3 tetrahedra, edges with six equivalent Cu(1)Ta2Se4 tetrahedra, and faces with four equivalent Se(1)TaCu3 tetrahedra. Cu(1) is bonded to two equivalent Ta(1) and four equivalent Se(1) atoms to form distorted CuTa2Se4 tetrahedra that share corners with two equivalent Cu(1)Ta2Se4 tetrahedra, corners with eight equivalent Se(1)TaCu3 tetrahedra, edges with two equivalent Ta(1)Cu6Se4 tetrahedra, and edges with eight equivalent Cu(1)Ta2Se4 tetrahedra. Se(1) is bonded to one Ta(1) and three equivalent Cu(1) atoms to form SeTaCu3 tetrahedra that share corners with three equivalent Ta(1)Cu6Se4 tetrahedra, corners with six equivalent Cu(1)Ta2Se4 tetrahedra, corners with six equivalent Se(1)TaCu3 tetrahedra, edges with three equivalent Se(1)TaCu3 tetrahedra, and  a faceface with one Ta(1)Cu6Se4 tetrahedra. is represented by the CIF card [CIF]
data_TaCu3Se4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.668
_cell_length_b   5.668
_cell_length_c   5.668
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   182.051
_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
  Ta  Ta0  1  0.000  0.000  0.000  1.0
  Cu  Cu1  1  0.500  0.000  0.000  1.0
  Cu  Cu2  1  0.000  0.000  0.500  1.0
  Cu  Cu3  1  0.000  0.500  0.000  1.0
  Se  Se4  1  0.249  0.249  0.249  1.0
  Se  Se5  1  0.751  0.751  0.249  1.0
  Se  Se6  1  0.751  0.249  0.751  1.0
  Se  Se7  1  0.249  0.751  0.751  1.0
[/CIF]
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The structure described by Cu3TaSe4 is Sulvanite structured and crystallizes in the cubic P-43m space group. Ta(1) is bonded to six equivalent Cu(1) and four equivalent Se(1) atoms to form distorted TaCu6Se4 tetrahedra that share corners with six equivalent Ta(1)Cu6Se4 tetrahedra, corners with twelve equivalent Se(1)TaCu3 tetrahedra, edges with six equivalent Cu(1)Ta2Se4 tetrahedra, and faces with four equivalent Se(1)TaCu3 tetrahedra. Cu(1) is bonded to two equivalent Ta(1) and four equivalent Se(1) atoms to form distorted CuTa2Se4 tetrahedra that share corners with two equivalent Cu(1)Ta2Se4 tetrahedra, corners with eight equivalent Se(1)TaCu3 tetrahedra, edges with two equivalent Ta(1)Cu6Se4 tetrahedra, and edges with eight equivalent Cu(1)Ta2Se4 tetrahedra. Se(1) is bonded to one Ta(1) and three equivalent Cu(1) atoms to form SeTaCu3 tetrahedra that share corners with three equivalent Ta(1)Cu6Se4 tetrahedra, corners with six equivalent Cu(1)Ta2Se4 tetrahedra, corners with six equivalent Se(1)TaCu3 tetrahedra, edges with three equivalent Se(1)TaCu3 tetrahedra, and  a faceface with one Ta(1)Cu6Se4 tetrahedra. is represented by the CIF card [CIF]
data_TaCu3Se4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.668
_cell_length_b   5.668
_cell_length_c   5.668
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   182.051
_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
  Ta  Ta0  1  0.000  0.000  0.000  1.0
  Cu  Cu1  1  0.500  0.000  0.000  1.0
  Cu  Cu2  1  0.000  0.000  0.500  1.0
  Cu  Cu3  1  0.000  0.500  0.000  1.0
  Se  Se4  1  0.249  0.249  0.249  1.0
  Se  Se5  1  0.751  0.751  0.249  1.0
  Se  Se6  1  0.751  0.249  0.751  1.0
  Se  Se7  1  0.249  0.751  0.751  1.0
[/CIF]
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