The crystal structure described by NaCuFeSe2 crystallizes in the trigonal P3m1 space group. Na(1) is bonded to three equivalent Se(1) and three equivalent Se(2) atoms to form NaSe6 octahedra that share corners with six equivalent Fe(1)Se4 tetrahedra, corners with six equivalent Cu(1)Se4 tetrahedra, edges with six equivalent Na(1)Se6 octahedra, edges with three equivalent Fe(1)Se4 tetrahedra, and edges with three equivalent Cu(1)Se4 tetrahedra. Fe(1) is bonded to one Se(2) and three equivalent Se(1) atoms to form FeSe4 tetrahedra that share corners with six equivalent Na(1)Se6 octahedra, corners with six equivalent Fe(1)Se4 tetrahedra, edges with three equivalent Na(1)Se6 octahedra, and edges with three equivalent Cu(1)Se4 tetrahedra. The corner-sharing octahedral tilt angles range from 19-51°. Cu(1) is bonded to one Se(1) and three equivalent Se(2) atoms to form distorted CuSe4 tetrahedra that share corners with six equivalent Na(1)Se6 octahedra, corners with six equivalent Cu(1)Se4 tetrahedra, edges with three equivalent Na(1)Se6 octahedra, and edges with three equivalent Fe(1)Se4 tetrahedra. The corner-sharing octahedral tilt angles range from 19-50°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Na(1), three equivalent Fe(1), and one Cu(1) atom to form distorted SeNa3Fe3Cu pentagonal bipyramids that share corners with three equivalent Se(2)Na3FeCu3 pentagonal bipyramids, edges with six equivalent Se(1)Na3Fe3Cu pentagonal bipyramids, and edges with six equivalent Se(2)Na3FeCu3 pentagonal bipyramids. In the second Se site, Se(2) is bonded to three equivalent Na(1), one Fe(1), and three equivalent Cu(1) atoms to form distorted SeNa3FeCu3 pentagonal bipyramids that share corners with three equivalent Se(1)Na3Fe3Cu pentagonal bipyramids, edges with six equivalent Se(1)Na3Fe3Cu pentagonal bipyramids, and edges with six equivalent Se(2)Na3FeCu3 pentagonal bipyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_NaFeCuSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.027
_cell_length_b   4.027
_cell_length_c   7.185
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   100.934
_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
  Na  Na0  1  0.000  0.000  0.008  1.0
  Fe  Fe1  1  0.333  0.667  0.608  1.0
  Cu  Cu2  1  0.667  0.333  0.384  1.0
  Se  Se3  1  0.667  0.333  0.735  1.0
  Se  Se4  1  0.333  0.667  0.266  1.0
[/CIF]
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The crystal structure described by NaCuFeSe2 crystallizes in the trigonal P3m1 space group. Na(1) is bonded to three equivalent Se(1) and three equivalent Se(2) atoms to form NaSe6 octahedra that share corners with six equivalent Fe(1)Se4 tetrahedra, corners with six equivalent Cu(1)Se4 tetrahedra, edges with six equivalent Na(1)Se6 octahedra, edges with three equivalent Fe(1)Se4 tetrahedra, and edges with three equivalent Cu(1)Se4 tetrahedra. Fe(1) is bonded to one Se(2) and three equivalent Se(1) atoms to form FeSe4 tetrahedra that share corners with six equivalent Na(1)Se6 octahedra, corners with six equivalent Fe(1)Se4 tetrahedra, edges with three equivalent Na(1)Se6 octahedra, and edges with three equivalent Cu(1)Se4 tetrahedra. The corner-sharing octahedral tilt angles range from 19-51°. Cu(1) is bonded to one Se(1) and three equivalent Se(2) atoms to form distorted CuSe4 tetrahedra that share corners with six equivalent Na(1)Se6 octahedra, corners with six equivalent Cu(1)Se4 tetrahedra, edges with three equivalent Na(1)Se6 octahedra, and edges with three equivalent Fe(1)Se4 tetrahedra. The corner-sharing octahedral tilt angles range from 19-50°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Na(1), three equivalent Fe(1), and one Cu(1) atom to form distorted SeNa3Fe3Cu pentagonal bipyramids that share corners with three equivalent Se(2)Na3FeCu3 pentagonal bipyramids, edges with six equivalent Se(1)Na3Fe3Cu pentagonal bipyramids, and edges with six equivalent Se(2)Na3FeCu3 pentagonal bipyramids. In the second Se site, Se(2) is bonded to three equivalent Na(1), one Fe(1), and three equivalent Cu(1) atoms to form distorted SeNa3FeCu3 pentagonal bipyramids that share corners with three equivalent Se(1)Na3Fe3Cu pentagonal bipyramids, edges with six equivalent Se(1)Na3Fe3Cu pentagonal bipyramids, and edges with six equivalent Se(2)Na3FeCu3 pentagonal bipyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_NaFeCuSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.027
_cell_length_b   4.027
_cell_length_c   7.185
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   100.934
_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
  Na  Na0  1  0.000  0.000  0.008  1.0
  Fe  Fe1  1  0.333  0.667  0.608  1.0
  Cu  Cu2  1  0.667  0.333  0.384  1.0
  Se  Se3  1  0.667  0.333  0.735  1.0
  Se  Se4  1  0.333  0.667  0.266  1.0
[/CIF]
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