The crystal structure described by Cr3NiCu2Se8 is Spinel-derived structured and crystallizes in the trigonal R-3m space group. Cr(1) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form CrSe6 octahedra that share corners with six equivalent Cu(1)Se4 tetrahedra, edges with two equivalent Ni(1)Se6 octahedra, and edges with four equivalent Cr(1)Se6 octahedra. Ni(1) is bonded to six equivalent Se(2) atoms to form NiSe6 octahedra that share corners with six equivalent Cu(1)Se4 tetrahedra and edges with six equivalent Cr(1)Se6 octahedra. Cu(1) is bonded to one Se(1) and three equivalent Se(2) atoms to form CuSe4 tetrahedra that share corners with three equivalent Ni(1)Se6 octahedra and corners with nine equivalent Cr(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 57-58°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Cr(1) and one Cu(1) atom. In the second Se site, Se(2) is bonded to two equivalent Cr(1), one Ni(1), and one Cu(1) atom to form a mixture of distorted edge and corner-sharing SeCr2CuNi trigonal pyramids. is represented by the CIF file [CIF]
data_Cr3Cu2NiSe8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.290
_cell_length_b   7.315
_cell_length_c   7.290
_cell_angle_alpha   90.000
_cell_angle_beta   60.000
_cell_angle_gamma   119.884
_symmetry_Int_Tables_number   1
_cell_volume   275.337
_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
  Cr  Cr0  1  0.500  0.500  0.500  1.0
  Cr  Cr1  1  0.000  0.500  0.000  1.0
  Cr  Cr2  1  0.000  0.500  0.500  1.0
  Cu  Cu3  1  0.250  0.125  0.125  1.0
  Cu  Cu4  1  0.750  0.875  0.875  1.0
  Ni  Ni5  1  0.500  0.000  0.500  1.0
  Se  Se6  1  0.984  0.726  0.258  1.0
  Se  Se7  1  0.982  0.257  0.259  1.0
  Se  Se8  1  0.516  0.257  0.725  1.0
  Se  Se9  1  0.516  0.257  0.259  1.0
  Se  Se10  1  0.016  0.274  0.742  1.0
  Se  Se11  1  0.018  0.743  0.741  1.0
  Se  Se12  1  0.484  0.743  0.275  1.0
  Se  Se13  1  0.484  0.743  0.741  1.0
[/CIF]
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The crystal structure described by Cr3NiCu2Se8 is Spinel-derived structured and crystallizes in the trigonal R-3m space group. Cr(1) is bonded to two equivalent Se(1) and four equivalent Se(2) atoms to form CrSe6 octahedra that share corners with six equivalent Cu(1)Se4 tetrahedra, edges with two equivalent Ni(1)Se6 octahedra, and edges with four equivalent Cr(1)Se6 octahedra. Ni(1) is bonded to six equivalent Se(2) atoms to form NiSe6 octahedra that share corners with six equivalent Cu(1)Se4 tetrahedra and edges with six equivalent Cr(1)Se6 octahedra. Cu(1) is bonded to one Se(1) and three equivalent Se(2) atoms to form CuSe4 tetrahedra that share corners with three equivalent Ni(1)Se6 octahedra and corners with nine equivalent Cr(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 57-58°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Cr(1) and one Cu(1) atom. In the second Se site, Se(2) is bonded to two equivalent Cr(1), one Ni(1), and one Cu(1) atom to form a mixture of distorted edge and corner-sharing SeCr2CuNi trigonal pyramids. is represented by the CIF file [CIF]
data_Cr3Cu2NiSe8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.290
_cell_length_b   7.315
_cell_length_c   7.290
_cell_angle_alpha   90.000
_cell_angle_beta   60.000
_cell_angle_gamma   119.884
_symmetry_Int_Tables_number   1
_cell_volume   275.337
_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
  Cr  Cr0  1  0.500  0.500  0.500  1.0
  Cr  Cr1  1  0.000  0.500  0.000  1.0
  Cr  Cr2  1  0.000  0.500  0.500  1.0
  Cu  Cu3  1  0.250  0.125  0.125  1.0
  Cu  Cu4  1  0.750  0.875  0.875  1.0
  Ni  Ni5  1  0.500  0.000  0.500  1.0
  Se  Se6  1  0.984  0.726  0.258  1.0
  Se  Se7  1  0.982  0.257  0.259  1.0
  Se  Se8  1  0.516  0.257  0.725  1.0
  Se  Se9  1  0.516  0.257  0.259  1.0
  Se  Se10  1  0.016  0.274  0.742  1.0
  Se  Se11  1  0.018  0.743  0.741  1.0
  Se  Se12  1  0.484  0.743  0.275  1.0
  Se  Se13  1  0.484  0.743  0.741  1.0
[/CIF]
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