The crystal structure described by CeSe2 crystallizes in the tetragonal I4_1/acd space group. The structure consists of a CeSe2 framework. Ce(1) is bonded to one Se(1), one Se(2), and two equivalent Se(3) atoms to form corner-sharing CeSe4 tetrahedra. There are three inequivalent Se sites. In the first Se site, Se(3) is bonded in a water-like geometry to two equivalent Ce(1) atoms. In the second Se site, Se(1) is bonded in a bent 120 degrees geometry to two equivalent Ce(1) atoms. In the third Se site, Se(2) is bonded in a water-like geometry to two equivalent Ce(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_CeSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   14.138
_cell_length_b   15.348
_cell_length_c   14.138
_cell_angle_alpha   62.576
_cell_angle_beta   90.000
_cell_angle_gamma   117.424
_symmetry_Int_Tables_number   1
_cell_volume   2327.639
_cell_formula_units_Z   16
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  0.908  0.617  0.569  1.0
  Ce  Ce1  1  0.209  0.617  0.069  1.0
  Ce  Ce2  1  0.431  0.117  0.092  1.0
  Ce  Ce3  1  0.187  0.117  0.592  1.0
  Ce  Ce4  1  0.092  0.383  0.431  1.0
  Ce  Ce5  1  0.791  0.383  0.931  1.0
  Ce  Ce6  1  0.569  0.883  0.908  1.0
  Ce  Ce7  1  0.813  0.883  0.408  1.0
  Ce  Ce8  1  0.408  0.617  0.813  1.0
  Ce  Ce9  1  0.709  0.617  0.313  1.0
  Ce  Ce10  1  0.931  0.117  0.791  1.0
  Ce  Ce11  1  0.687  0.117  0.291  1.0
  Ce  Ce12  1  0.592  0.383  0.187  1.0
  Ce  Ce13  1  0.291  0.383  0.687  1.0
  Ce  Ce14  1  0.069  0.883  0.209  1.0
  Ce  Ce15  1  0.313  0.883  0.709  1.0
  Se  Se16  1  0.755  0.509  0.995  1.0
  Se  Se17  1  0.255  0.509  0.495  1.0
  Se  Se18  1  0.005  0.009  0.245  1.0
  Se  Se19  1  0.505  0.009  0.745  1.0
  Se  Se20  1  0.245  0.491  0.005  1.0
  Se  Se21  1  0.745  0.491  0.505  1.0
  Se  Se22  1  0.995  0.991  0.755  1.0
  Se  Se23  1  0.495  0.991  0.255  1.0
  Se  Se24  1  0.750  0.000  0.462  1.0
  Se  Se25  1  0.750  0.000  0.962  1.0
  Se  Se26  1  0.538  0.500  0.250  1.0
  Se  Se27  1  0.462  0.500  0.750  1.0
  Se  Se28  1  0.250  0.000  0.538  1.0
  Se  Se29  1  0.250  0.000  0.038  1.0
  Se  Se30  1  0.038  0.500  0.250  1.0
  Se  Se31  1  0.962  0.500  0.750  1.0
  Se  Se32  1  0.902  0.248  0.596  1.0
  Se  Se33  1  0.846  0.248  0.096  1.0
  Se  Se34  1  0.404  0.748  0.098  1.0
  Se  Se35  1  0.844  0.748  0.598  1.0
  Se  Se36  1  0.098  0.752  0.404  1.0
  Se  Se37  1  0.154  0.752  0.904  1.0
  Se  Se38  1  0.596  0.252  0.902  1.0
  Se  Se39  1  0.156  0.252  0.402  1.0
  Se  Se40  1  0.402  0.248  0.156  1.0
  Se  Se41  1  0.346  0.248  0.656  1.0
  Se  Se42  1  0.904  0.748  0.154  1.0
  Se  Se43  1  0.344  0.748  0.654  1.0
  Se  Se44  1  0.598  0.752  0.844  1.0
  Se  Se45  1  0.654  0.752  0.344  1.0
  Se  Se46  1  0.096  0.252  0.846  1.0
  Se  Se47  1  0.656  0.252  0.346  1.0
[/CIF]
.
The crystal structure described by CeSe2 crystallizes in the tetragonal I4_1/acd space group. The structure consists of a CeSe2 framework. Ce(1) is bonded to one Se(1), one Se(2), and two equivalent Se(3) atoms to form corner-sharing CeSe4 tetrahedra. There are three inequivalent Se sites. In the first Se site, Se(3) is bonded in a water-like geometry to two equivalent Ce(1) atoms. In the second Se site, Se(1) is bonded in a bent 120 degrees geometry to two equivalent Ce(1) atoms. In the third Se site, Se(2) is bonded in a water-like geometry to two equivalent Ce(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_CeSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   14.138
_cell_length_b   15.348
_cell_length_c   14.138
_cell_angle_alpha   62.576
_cell_angle_beta   90.000
_cell_angle_gamma   117.424
_symmetry_Int_Tables_number   1
_cell_volume   2327.639
_cell_formula_units_Z   16
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  0.908  0.617  0.569  1.0
  Ce  Ce1  1  0.209  0.617  0.069  1.0
  Ce  Ce2  1  0.431  0.117  0.092  1.0
  Ce  Ce3  1  0.187  0.117  0.592  1.0
  Ce  Ce4  1  0.092  0.383  0.431  1.0
  Ce  Ce5  1  0.791  0.383  0.931  1.0
  Ce  Ce6  1  0.569  0.883  0.908  1.0
  Ce  Ce7  1  0.813  0.883  0.408  1.0
  Ce  Ce8  1  0.408  0.617  0.813  1.0
  Ce  Ce9  1  0.709  0.617  0.313  1.0
  Ce  Ce10  1  0.931  0.117  0.791  1.0
  Ce  Ce11  1  0.687  0.117  0.291  1.0
  Ce  Ce12  1  0.592  0.383  0.187  1.0
  Ce  Ce13  1  0.291  0.383  0.687  1.0
  Ce  Ce14  1  0.069  0.883  0.209  1.0
  Ce  Ce15  1  0.313  0.883  0.709  1.0
  Se  Se16  1  0.755  0.509  0.995  1.0
  Se  Se17  1  0.255  0.509  0.495  1.0
  Se  Se18  1  0.005  0.009  0.245  1.0
  Se  Se19  1  0.505  0.009  0.745  1.0
  Se  Se20  1  0.245  0.491  0.005  1.0
  Se  Se21  1  0.745  0.491  0.505  1.0
  Se  Se22  1  0.995  0.991  0.755  1.0
  Se  Se23  1  0.495  0.991  0.255  1.0
  Se  Se24  1  0.750  0.000  0.462  1.0
  Se  Se25  1  0.750  0.000  0.962  1.0
  Se  Se26  1  0.538  0.500  0.250  1.0
  Se  Se27  1  0.462  0.500  0.750  1.0
  Se  Se28  1  0.250  0.000  0.538  1.0
  Se  Se29  1  0.250  0.000  0.038  1.0
  Se  Se30  1  0.038  0.500  0.250  1.0
  Se  Se31  1  0.962  0.500  0.750  1.0
  Se  Se32  1  0.902  0.248  0.596  1.0
  Se  Se33  1  0.846  0.248  0.096  1.0
  Se  Se34  1  0.404  0.748  0.098  1.0
  Se  Se35  1  0.844  0.748  0.598  1.0
  Se  Se36  1  0.098  0.752  0.404  1.0
  Se  Se37  1  0.154  0.752  0.904  1.0
  Se  Se38  1  0.596  0.252  0.902  1.0
  Se  Se39  1  0.156  0.252  0.402  1.0
  Se  Se40  1  0.402  0.248  0.156  1.0
  Se  Se41  1  0.346  0.248  0.656  1.0
  Se  Se42  1  0.904  0.748  0.154  1.0
  Se  Se43  1  0.344  0.748  0.654  1.0
  Se  Se44  1  0.598  0.752  0.844  1.0
  Se  Se45  1  0.654  0.752  0.344  1.0
  Se  Se46  1  0.096  0.252  0.846  1.0
  Se  Se47  1  0.656  0.252  0.346  1.0
[/CIF]
.