The crystal structure described by CeSe2 crystallizes in the trigonal P-31m space group. Ce(1) is bonded to one Se(1), one Se(3), and two equivalent Se(2) atoms to form distorted corner-sharing CeSe4 trigonal pyramids. There are three inequivalent Se sites. In the first Se site, Se(2) is bonded in a linear geometry to two equivalent Ce(1) atoms. In the second Se site, Se(1) is bonded in a linear geometry to two equivalent Ce(1) atoms. In the third Se site, Se(3) is bonded in a linear geometry to two equivalent Ce(1) atoms. is represented by the CIF card [CIF]
data_CeSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   14.334
_cell_length_b   14.334
_cell_length_c   5.810
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   1033.796
_cell_formula_units_Z   6
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
  Ce  Ce0  1  0.000  0.664  0.271  1.0
  Ce  Ce1  1  0.664  0.000  0.271  1.0
  Ce  Ce2  1  0.336  0.336  0.271  1.0
  Ce  Ce3  1  0.000  0.336  0.729  1.0
  Ce  Ce4  1  0.336  0.000  0.729  1.0
  Ce  Ce5  1  0.664  0.664  0.729  1.0
  Se  Se6  1  0.000  0.500  0.500  1.0
  Se  Se7  1  0.500  0.000  0.500  1.0
  Se  Se8  1  0.500  0.500  0.500  1.0
  Se  Se9  1  0.167  0.833  0.500  1.0
  Se  Se10  1  0.665  0.833  0.500  1.0
  Se  Se11  1  0.167  0.335  0.500  1.0
  Se  Se12  1  0.833  0.665  0.500  1.0
  Se  Se13  1  0.833  0.167  0.500  1.0
  Se  Se14  1  0.335  0.167  0.500  1.0
  Se  Se15  1  0.000  0.500  0.000  1.0
  Se  Se16  1  0.500  0.000  0.000  1.0
  Se  Se17  1  0.500  0.500  0.000  1.0
[/CIF]
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The crystal structure described by CeSe2 crystallizes in the trigonal P-31m space group. Ce(1) is bonded to one Se(1), one Se(3), and two equivalent Se(2) atoms to form distorted corner-sharing CeSe4 trigonal pyramids. There are three inequivalent Se sites. In the first Se site, Se(2) is bonded in a linear geometry to two equivalent Ce(1) atoms. In the second Se site, Se(1) is bonded in a linear geometry to two equivalent Ce(1) atoms. In the third Se site, Se(3) is bonded in a linear geometry to two equivalent Ce(1) atoms. is represented by the CIF card [CIF]
data_CeSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   14.334
_cell_length_b   14.334
_cell_length_c   5.810
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   1033.796
_cell_formula_units_Z   6
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
  Ce  Ce0  1  0.000  0.664  0.271  1.0
  Ce  Ce1  1  0.664  0.000  0.271  1.0
  Ce  Ce2  1  0.336  0.336  0.271  1.0
  Ce  Ce3  1  0.000  0.336  0.729  1.0
  Ce  Ce4  1  0.336  0.000  0.729  1.0
  Ce  Ce5  1  0.664  0.664  0.729  1.0
  Se  Se6  1  0.000  0.500  0.500  1.0
  Se  Se7  1  0.500  0.000  0.500  1.0
  Se  Se8  1  0.500  0.500  0.500  1.0
  Se  Se9  1  0.167  0.833  0.500  1.0
  Se  Se10  1  0.665  0.833  0.500  1.0
  Se  Se11  1  0.167  0.335  0.500  1.0
  Se  Se12  1  0.833  0.665  0.500  1.0
  Se  Se13  1  0.833  0.167  0.500  1.0
  Se  Se14  1  0.335  0.167  0.500  1.0
  Se  Se15  1  0.000  0.500  0.000  1.0
  Se  Se16  1  0.500  0.000  0.000  1.0
  Se  Se17  1  0.500  0.500  0.000  1.0
[/CIF]
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