The crystal structure described by CuFeSe2 is Sulvanite-like structured and crystallizes in the tetragonal P-42m space group. Fe(1) is bonded to four equivalent Se(1) atoms to form distorted FeSe4 tetrahedra that share corners with four equivalent Fe(1)Se4 tetrahedra, corners with four equivalent Cu(2)Se4 tetrahedra, and edges with two equivalent Cu(1)Se4 tetrahedra. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to four equivalent Se(1) atoms to form distorted CuSe4 tetrahedra that share edges with two equivalent Cu(2)Se4 tetrahedra and edges with four equivalent Fe(1)Se4 tetrahedra. In the second Cu site, Cu(2) is bonded to four equivalent Se(1) atoms to form CuSe4 tetrahedra that share corners with eight equivalent Fe(1)Se4 tetrahedra and edges with two equivalent Cu(1)Se4 tetrahedra. Se(1) is bonded to two equivalent Fe(1), one Cu(1), and one Cu(2) atom to form a mixture of distorted edge and corner-sharing SeFe2Cu2 tetrahedra. is represented by the CIF file [CIF]
data_FeCuSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.463
_cell_length_b   5.463
_cell_length_c   5.615
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   167.550
_cell_formula_units_Z   2
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
  Fe  Fe0  1  0.500  0.000  0.000  1.0
  Fe  Fe1  1  0.000  0.500  0.000  1.0
  Cu  Cu2  1  0.000  0.000  0.000  1.0
  Cu  Cu3  1  0.000  0.000  0.500  1.0
  Se  Se4  1  0.738  0.262  0.254  1.0
  Se  Se5  1  0.262  0.262  0.746  1.0
  Se  Se6  1  0.738  0.738  0.746  1.0
  Se  Se7  1  0.262  0.738  0.254  1.0
[/CIF]
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The crystal structure described by CuFeSe2 is Sulvanite-like structured and crystallizes in the tetragonal P-42m space group. Fe(1) is bonded to four equivalent Se(1) atoms to form distorted FeSe4 tetrahedra that share corners with four equivalent Fe(1)Se4 tetrahedra, corners with four equivalent Cu(2)Se4 tetrahedra, and edges with two equivalent Cu(1)Se4 tetrahedra. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to four equivalent Se(1) atoms to form distorted CuSe4 tetrahedra that share edges with two equivalent Cu(2)Se4 tetrahedra and edges with four equivalent Fe(1)Se4 tetrahedra. In the second Cu site, Cu(2) is bonded to four equivalent Se(1) atoms to form CuSe4 tetrahedra that share corners with eight equivalent Fe(1)Se4 tetrahedra and edges with two equivalent Cu(1)Se4 tetrahedra. Se(1) is bonded to two equivalent Fe(1), one Cu(1), and one Cu(2) atom to form a mixture of distorted edge and corner-sharing SeFe2Cu2 tetrahedra. is represented by the CIF file [CIF]
data_FeCuSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.463
_cell_length_b   5.463
_cell_length_c   5.615
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   167.550
_cell_formula_units_Z   2
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
  Fe  Fe0  1  0.500  0.000  0.000  1.0
  Fe  Fe1  1  0.000  0.500  0.000  1.0
  Cu  Cu2  1  0.000  0.000  0.000  1.0
  Cu  Cu3  1  0.000  0.000  0.500  1.0
  Se  Se4  1  0.738  0.262  0.254  1.0
  Se  Se5  1  0.262  0.262  0.746  1.0
  Se  Se6  1  0.738  0.738  0.746  1.0
  Se  Se7  1  0.262  0.738  0.254  1.0
[/CIF]
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