The material described by CuCrSe2 crystallizes in the trigonal R3m space group. Cr(1) is bonded to one Cu(1), three equivalent Se(1), and three equivalent Se(2) atoms to form distorted CrCuSe6 octahedra that share  a cornercorner with one Se(1)Cr3Cu trigonal pyramid and edges with six equivalent Cr(1)CuSe6 octahedra. Cu(1) is bonded in a 4-coordinate geometry to one Cr(1), one Se(1), and three equivalent Se(2) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Cr(1) and one Cu(1) atom to form distorted SeCr3Cu trigonal pyramids that share  a cornercorner with one Cr(1)CuSe6 octahedra and corners with six equivalent Se(1)Cr3Cu trigonal pyramids. The corner-sharing octahedra are not tilted. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to three equivalent Cr(1) and three equivalent Cu(1) atoms. is represented by the CIF file [CIF]
data_CrCuSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.748
_cell_length_b   3.748
_cell_length_c   6.726
_cell_angle_alpha   73.821
_cell_angle_beta   73.821
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   77.498
_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  0.001  0.001  0.998  1.0
  Cu  Cu1  1  0.857  0.857  0.428  1.0
  Se  Se2  1  0.735  0.735  0.796  1.0
  Se  Se3  1  0.255  0.255  0.234  1.0
[/CIF]
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The material described by CuCrSe2 crystallizes in the trigonal R3m space group. Cr(1) is bonded to one Cu(1), three equivalent Se(1), and three equivalent Se(2) atoms to form distorted CrCuSe6 octahedra that share  a cornercorner with one Se(1)Cr3Cu trigonal pyramid and edges with six equivalent Cr(1)CuSe6 octahedra. Cu(1) is bonded in a 4-coordinate geometry to one Cr(1), one Se(1), and three equivalent Se(2) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Cr(1) and one Cu(1) atom to form distorted SeCr3Cu trigonal pyramids that share  a cornercorner with one Cr(1)CuSe6 octahedra and corners with six equivalent Se(1)Cr3Cu trigonal pyramids. The corner-sharing octahedra are not tilted. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to three equivalent Cr(1) and three equivalent Cu(1) atoms. is represented by the CIF file [CIF]
data_CrCuSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.748
_cell_length_b   3.748
_cell_length_c   6.726
_cell_angle_alpha   73.821
_cell_angle_beta   73.821
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   77.498
_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  0.001  0.001  0.998  1.0
  Cu  Cu1  1  0.857  0.857  0.428  1.0
  Se  Se2  1  0.735  0.735  0.796  1.0
  Se  Se3  1  0.255  0.255  0.234  1.0
[/CIF]
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