The material described by TmCuSe2 crystallizes in the trigonal P3m1 space group. Tm(1) is bonded to three equivalent Se(1) and three equivalent Se(2) atoms to form TmSe6 octahedra that share corners with six equivalent Cu(1)Se4 tetrahedra, edges with six equivalent Tm(1)Se6 octahedra, and edges with three equivalent Cu(1)Se4 tetrahedra. Cu(1) is bonded to one Se(2) and three equivalent Se(1) atoms to form CuSe4 tetrahedra that share corners with six equivalent Tm(1)Se6 octahedra, corners with six equivalent Cu(1)Se4 tetrahedra, and edges with three equivalent Tm(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 19-58°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Tm(1) and three equivalent Cu(1) atoms to form distorted SeTm3Cu3 octahedra that share corners with six equivalent Se(2)Tm3Cu trigonal pyramids, edges with six equivalent Se(1)Tm3Cu3 octahedra, and edges with three equivalent Se(2)Tm3Cu trigonal pyramids. In the second Se site, Se(2) is bonded to three equivalent Tm(1) and one Cu(1) atom to form distorted SeTm3Cu trigonal pyramids that share corners with six equivalent Se(1)Tm3Cu3 octahedra, corners with six equivalent Se(2)Tm3Cu trigonal pyramids, and edges with three equivalent Se(1)Tm3Cu3 octahedra. The corner-sharing octahedral tilt angles range from 4-73°. is represented by the CIF card [CIF]
data_TmCuSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.037
_cell_length_b   4.037
_cell_length_c   6.352
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   89.641
_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
  Tm  Tm0  1  0.000  0.000  0.800  1.0
  Cu  Cu1  1  0.667  0.333  0.185  1.0
  Se  Se2  1  0.333  0.667  0.070  1.0
  Se  Se3  1  0.667  0.333  0.566  1.0
[/CIF]
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The material described by TmCuSe2 crystallizes in the trigonal P3m1 space group. Tm(1) is bonded to three equivalent Se(1) and three equivalent Se(2) atoms to form TmSe6 octahedra that share corners with six equivalent Cu(1)Se4 tetrahedra, edges with six equivalent Tm(1)Se6 octahedra, and edges with three equivalent Cu(1)Se4 tetrahedra. Cu(1) is bonded to one Se(2) and three equivalent Se(1) atoms to form CuSe4 tetrahedra that share corners with six equivalent Tm(1)Se6 octahedra, corners with six equivalent Cu(1)Se4 tetrahedra, and edges with three equivalent Tm(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 19-58°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Tm(1) and three equivalent Cu(1) atoms to form distorted SeTm3Cu3 octahedra that share corners with six equivalent Se(2)Tm3Cu trigonal pyramids, edges with six equivalent Se(1)Tm3Cu3 octahedra, and edges with three equivalent Se(2)Tm3Cu trigonal pyramids. In the second Se site, Se(2) is bonded to three equivalent Tm(1) and one Cu(1) atom to form distorted SeTm3Cu trigonal pyramids that share corners with six equivalent Se(1)Tm3Cu3 octahedra, corners with six equivalent Se(2)Tm3Cu trigonal pyramids, and edges with three equivalent Se(1)Tm3Cu3 octahedra. The corner-sharing octahedral tilt angles range from 4-73°. is represented by the CIF card [CIF]
data_TmCuSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.037
_cell_length_b   4.037
_cell_length_c   6.352
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   89.641
_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
  Tm  Tm0  1  0.000  0.000  0.800  1.0
  Cu  Cu1  1  0.667  0.333  0.185  1.0
  Se  Se2  1  0.333  0.667  0.070  1.0
  Se  Se3  1  0.667  0.333  0.566  1.0
[/CIF]
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