The crystal structure described by CeSe2 crystallizes in the hexagonal P6_3/mmc space group. Ce(1) is bonded to one Se(1), one Se(3), and two equivalent Se(2) atoms to form corner-sharing CeSe4 tetrahedra. There are three inequivalent Se sites. In the first Se site, Se(2) is bonded in a bent 120 degrees 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 bent 150 degrees 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   16.907
_cell_length_b   16.907
_cell_length_c   17.309
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   4284.611
_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  0.570  0.139  0.896  1.0
  Ce  Ce1  1  0.570  0.430  0.896  1.0
  Ce  Ce2  1  0.861  0.430  0.896  1.0
  Ce  Ce3  1  0.430  0.861  0.104  1.0
  Ce  Ce4  1  0.430  0.570  0.104  1.0
  Ce  Ce5  1  0.139  0.570  0.104  1.0
  Ce  Ce6  1  0.430  0.861  0.396  1.0
  Ce  Ce7  1  0.430  0.570  0.396  1.0
  Ce  Ce8  1  0.139  0.570  0.396  1.0
  Ce  Ce9  1  0.570  0.139  0.604  1.0
  Ce  Ce10  1  0.570  0.430  0.604  1.0
  Ce  Ce11  1  0.861  0.430  0.604  1.0
  Se  Se12  1  0.000  0.500  0.000  1.0
  Se  Se13  1  0.500  0.000  0.000  1.0
  Se  Se14  1  0.500  0.500  0.000  1.0
  Se  Se15  1  0.000  0.500  0.500  1.0
  Se  Se16  1  0.500  0.000  0.500  1.0
  Se  Se17  1  0.500  0.500  0.500  1.0
  Se  Se18  1  0.495  0.247  0.915  1.0
  Se  Se19  1  0.753  0.505  0.915  1.0
  Se  Se20  1  0.753  0.247  0.915  1.0
  Se  Se21  1  0.505  0.753  0.085  1.0
  Se  Se22  1  0.247  0.495  0.085  1.0
  Se  Se23  1  0.247  0.753  0.085  1.0
  Se  Se24  1  0.505  0.753  0.415  1.0
  Se  Se25  1  0.247  0.495  0.415  1.0
  Se  Se26  1  0.247  0.753  0.415  1.0
  Se  Se27  1  0.495  0.247  0.585  1.0
  Se  Se28  1  0.753  0.505  0.585  1.0
  Se  Se29  1  0.753  0.247  0.585  1.0
  Se  Se30  1  0.069  0.535  0.250  1.0
  Se  Se31  1  0.465  0.931  0.250  1.0
  Se  Se32  1  0.465  0.535  0.250  1.0
  Se  Se33  1  0.931  0.465  0.750  1.0
  Se  Se34  1  0.535  0.069  0.750  1.0
  Se  Se35  1  0.535  0.465  0.750  1.0
[/CIF]
.
The crystal structure described by CeSe2 crystallizes in the hexagonal P6_3/mmc space group. Ce(1) is bonded to one Se(1), one Se(3), and two equivalent Se(2) atoms to form corner-sharing CeSe4 tetrahedra. There are three inequivalent Se sites. In the first Se site, Se(2) is bonded in a bent 120 degrees 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 bent 150 degrees 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   16.907
_cell_length_b   16.907
_cell_length_c   17.309
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   4284.611
_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  0.570  0.139  0.896  1.0
  Ce  Ce1  1  0.570  0.430  0.896  1.0
  Ce  Ce2  1  0.861  0.430  0.896  1.0
  Ce  Ce3  1  0.430  0.861  0.104  1.0
  Ce  Ce4  1  0.430  0.570  0.104  1.0
  Ce  Ce5  1  0.139  0.570  0.104  1.0
  Ce  Ce6  1  0.430  0.861  0.396  1.0
  Ce  Ce7  1  0.430  0.570  0.396  1.0
  Ce  Ce8  1  0.139  0.570  0.396  1.0
  Ce  Ce9  1  0.570  0.139  0.604  1.0
  Ce  Ce10  1  0.570  0.430  0.604  1.0
  Ce  Ce11  1  0.861  0.430  0.604  1.0
  Se  Se12  1  0.000  0.500  0.000  1.0
  Se  Se13  1  0.500  0.000  0.000  1.0
  Se  Se14  1  0.500  0.500  0.000  1.0
  Se  Se15  1  0.000  0.500  0.500  1.0
  Se  Se16  1  0.500  0.000  0.500  1.0
  Se  Se17  1  0.500  0.500  0.500  1.0
  Se  Se18  1  0.495  0.247  0.915  1.0
  Se  Se19  1  0.753  0.505  0.915  1.0
  Se  Se20  1  0.753  0.247  0.915  1.0
  Se  Se21  1  0.505  0.753  0.085  1.0
  Se  Se22  1  0.247  0.495  0.085  1.0
  Se  Se23  1  0.247  0.753  0.085  1.0
  Se  Se24  1  0.505  0.753  0.415  1.0
  Se  Se25  1  0.247  0.495  0.415  1.0
  Se  Se26  1  0.247  0.753  0.415  1.0
  Se  Se27  1  0.495  0.247  0.585  1.0
  Se  Se28  1  0.753  0.505  0.585  1.0
  Se  Se29  1  0.753  0.247  0.585  1.0
  Se  Se30  1  0.069  0.535  0.250  1.0
  Se  Se31  1  0.465  0.931  0.250  1.0
  Se  Se32  1  0.465  0.535  0.250  1.0
  Se  Se33  1  0.931  0.465  0.750  1.0
  Se  Se34  1  0.535  0.069  0.750  1.0
  Se  Se35  1  0.535  0.465  0.750  1.0
[/CIF]
.