The structure described by CeSe2 crystallizes in the trigonal R-3m space group. Ce(1) is bonded to one Se(1), one Se(2), one Se(3), and one Se(4) atom to form corner-sharing CeSe4 tetrahedra. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a bent 120 degrees geometry to two equivalent Ce(1) atoms. In the second Se site, Se(2) is bonded in a bent 120 degrees geometry to two equivalent Ce(1) atoms. In the third Se site, Se(3) is bonded in a bent 150 degrees geometry to two equivalent Ce(1) atoms. In the fourth Se site, Se(4) is bonded in a bent 150 degrees geometry to two equivalent Ce(1) atoms. is represented by the CIF file [CIF]
data_CeSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.402
_cell_length_b   18.046
_cell_length_c   18.046
_cell_angle_alpha   115.688
_cell_angle_beta   102.158
_cell_angle_gamma   102.158
_symmetry_Int_Tables_number   1
_cell_volume   3072.869
_cell_formula_units_Z   12
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  0.199  0.841  0.433  1.0
  Ce  Ce1  1  0.765  0.567  0.408  1.0
  Ce  Ce2  1  0.357  0.592  0.159  1.0
  Ce  Ce3  1  0.357  0.159  0.592  1.0
  Ce  Ce4  1  0.765  0.408  0.567  1.0
  Ce  Ce5  1  0.199  0.433  0.841  1.0
  Ce  Ce6  1  0.801  0.159  0.567  1.0
  Ce  Ce7  1  0.235  0.433  0.592  1.0
  Ce  Ce8  1  0.643  0.408  0.841  1.0
  Ce  Ce9  1  0.643  0.841  0.408  1.0
  Ce  Ce10  1  0.235  0.592  0.433  1.0
  Ce  Ce11  1  0.801  0.567  0.159  1.0
  Se  Se12  1  0.736  0.472  0.236  1.0
  Se  Se13  1  0.500  0.764  0.236  1.0
  Se  Se14  1  0.264  0.764  0.528  1.0
  Se  Se15  1  0.264  0.528  0.764  1.0
  Se  Se16  1  0.500  0.236  0.764  1.0
  Se  Se17  1  0.736  0.236  0.472  1.0
  Se  Se18  1  0.833  0.000  0.480  1.0
  Se  Se19  1  0.352  0.520  0.520  1.0
  Se  Se20  1  0.833  0.480  0.000  1.0
  Se  Se21  1  0.168  0.000  0.520  1.0
  Se  Se22  1  0.648  0.480  0.480  1.0
  Se  Se23  1  0.168  0.520  0.000  1.0
  Se  Se24  1  0.553  0.553  0.107  1.0
  Se  Se25  1  0.447  0.893  0.447  1.0
  Se  Se26  1  0.000  0.553  0.447  1.0
  Se  Se27  1  0.000  0.447  0.553  1.0
  Se  Se28  1  0.447  0.447  0.893  1.0
  Se  Se29  1  0.553  0.107  0.553  1.0
  Se  Se30  1  1.000  0.719  0.281  1.0
  Se  Se31  1  0.719  0.719  0.439  1.0
  Se  Se32  1  0.281  0.561  0.281  1.0
  Se  Se33  1  0.281  0.281  0.561  1.0
  Se  Se34  1  0.719  0.439  0.719  1.0
  Se  Se35  1  1.000  0.281  0.719  1.0
[/CIF]
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The structure described by CeSe2 crystallizes in the trigonal R-3m space group. Ce(1) is bonded to one Se(1), one Se(2), one Se(3), and one Se(4) atom to form corner-sharing CeSe4 tetrahedra. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a bent 120 degrees geometry to two equivalent Ce(1) atoms. In the second Se site, Se(2) is bonded in a bent 120 degrees geometry to two equivalent Ce(1) atoms. In the third Se site, Se(3) is bonded in a bent 150 degrees geometry to two equivalent Ce(1) atoms. In the fourth Se site, Se(4) is bonded in a bent 150 degrees geometry to two equivalent Ce(1) atoms. is represented by the CIF file [CIF]
data_CeSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.402
_cell_length_b   18.046
_cell_length_c   18.046
_cell_angle_alpha   115.688
_cell_angle_beta   102.158
_cell_angle_gamma   102.158
_symmetry_Int_Tables_number   1
_cell_volume   3072.869
_cell_formula_units_Z   12
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  0.199  0.841  0.433  1.0
  Ce  Ce1  1  0.765  0.567  0.408  1.0
  Ce  Ce2  1  0.357  0.592  0.159  1.0
  Ce  Ce3  1  0.357  0.159  0.592  1.0
  Ce  Ce4  1  0.765  0.408  0.567  1.0
  Ce  Ce5  1  0.199  0.433  0.841  1.0
  Ce  Ce6  1  0.801  0.159  0.567  1.0
  Ce  Ce7  1  0.235  0.433  0.592  1.0
  Ce  Ce8  1  0.643  0.408  0.841  1.0
  Ce  Ce9  1  0.643  0.841  0.408  1.0
  Ce  Ce10  1  0.235  0.592  0.433  1.0
  Ce  Ce11  1  0.801  0.567  0.159  1.0
  Se  Se12  1  0.736  0.472  0.236  1.0
  Se  Se13  1  0.500  0.764  0.236  1.0
  Se  Se14  1  0.264  0.764  0.528  1.0
  Se  Se15  1  0.264  0.528  0.764  1.0
  Se  Se16  1  0.500  0.236  0.764  1.0
  Se  Se17  1  0.736  0.236  0.472  1.0
  Se  Se18  1  0.833  0.000  0.480  1.0
  Se  Se19  1  0.352  0.520  0.520  1.0
  Se  Se20  1  0.833  0.480  0.000  1.0
  Se  Se21  1  0.168  0.000  0.520  1.0
  Se  Se22  1  0.648  0.480  0.480  1.0
  Se  Se23  1  0.168  0.520  0.000  1.0
  Se  Se24  1  0.553  0.553  0.107  1.0
  Se  Se25  1  0.447  0.893  0.447  1.0
  Se  Se26  1  0.000  0.553  0.447  1.0
  Se  Se27  1  0.000  0.447  0.553  1.0
  Se  Se28  1  0.447  0.447  0.893  1.0
  Se  Se29  1  0.553  0.107  0.553  1.0
  Se  Se30  1  1.000  0.719  0.281  1.0
  Se  Se31  1  0.719  0.719  0.439  1.0
  Se  Se32  1  0.281  0.561  0.281  1.0
  Se  Se33  1  0.281  0.281  0.561  1.0
  Se  Se34  1  0.719  0.439  0.719  1.0
  Se  Se35  1  1.000  0.281  0.719  1.0
[/CIF]
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