The material described by CeSe2 is Low Tridymite-like structured and crystallizes in the tetragonal I4_1/amd space group. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to two equivalent Se(1) and two equivalent Se(2) atoms to form corner-sharing CeSe4 tetrahedra. In the second Ce site, Ce(2) is bonded to one Se(3), one Se(4), and two equivalent Se(1) atoms to form corner-sharing CeSe4 tetrahedra. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(2) atom. In the second Se site, Se(2) is bonded in a distorted bent 120 degrees geometry to two equivalent Ce(1) atoms. In the third Se site, Se(3) is bonded in a linear geometry to two equivalent Ce(2) atoms. In the fourth Se site, Se(4) is bonded in a linear geometry to two equivalent Ce(2) atoms. is represented by the CIF file [CIF]
data_CeSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.111
_cell_length_b   13.111
_cell_length_c   25.294
_cell_angle_alpha   105.021
_cell_angle_beta   105.021
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   4045.584
_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  0.434  0.184  0.250  1.0
  Ce  Ce1  1  0.434  0.566  0.250  1.0
  Ce  Ce2  1  0.184  0.434  0.750  1.0
  Ce  Ce3  1  0.184  0.816  0.750  1.0
  Ce  Ce4  1  0.816  0.184  0.250  1.0
  Ce  Ce5  1  0.816  0.566  0.250  1.0
  Ce  Ce6  1  0.566  0.434  0.750  1.0
  Ce  Ce7  1  0.566  0.816  0.750  1.0
  Ce  Ce8  1  0.986  0.943  0.387  1.0
  Ce  Ce9  1  0.943  0.986  0.887  1.0
  Ce  Ce10  1  0.943  0.400  0.887  1.0
  Ce  Ce11  1  0.400  0.943  0.387  1.0
  Ce  Ce12  1  0.014  0.057  0.613  1.0
  Ce  Ce13  1  0.057  0.014  0.113  1.0
  Ce  Ce14  1  0.057  0.600  0.113  1.0
  Ce  Ce15  1  0.600  0.057  0.613  1.0
  Se  Se16  1  0.437  0.096  0.337  1.0
  Se  Se17  1  0.437  0.741  0.337  1.0
  Se  Se18  1  0.096  0.437  0.837  1.0
  Se  Se19  1  0.096  0.899  0.837  1.0
  Se  Se20  1  0.899  0.096  0.337  1.0
  Se  Se21  1  0.899  0.741  0.337  1.0
  Se  Se22  1  0.741  0.437  0.837  1.0
  Se  Se23  1  0.741  0.899  0.837  1.0
  Se  Se24  1  0.563  0.904  0.663  1.0
  Se  Se25  1  0.563  0.259  0.663  1.0
  Se  Se26  1  0.904  0.563  0.163  1.0
  Se  Se27  1  0.904  0.101  0.163  1.0
  Se  Se28  1  0.101  0.904  0.663  1.0
  Se  Se29  1  0.101  0.259  0.663  1.0
  Se  Se30  1  0.259  0.563  0.163  1.0
  Se  Se31  1  0.259  0.101  0.163  1.0
  Se  Se32  1  0.132  0.604  0.709  1.0
  Se  Se33  1  0.604  0.132  0.209  1.0
  Se  Se34  1  0.604  0.577  0.209  1.0
  Se  Se35  1  0.577  0.604  0.709  1.0
  Se  Se36  1  0.868  0.396  0.291  1.0
  Se  Se37  1  0.396  0.868  0.791  1.0
  Se  Se38  1  0.396  0.423  0.791  1.0
  Se  Se39  1  0.423  0.396  0.291  1.0
  Se  Se40  1  0.190  0.940  0.381  1.0
  Se  Se41  1  0.940  0.190  0.881  1.0
  Se  Se42  1  0.810  0.060  0.619  1.0
  Se  Se43  1  0.060  0.810  0.119  1.0
  Se  Se44  1  0.000  0.000  0.500  1.0
  Se  Se45  1  0.000  0.000  0.000  1.0
  Se  Se46  1  0.000  0.500  0.000  1.0
  Se  Se47  1  0.500  0.000  0.500  1.0
[/CIF]
.
The material described by CeSe2 is Low Tridymite-like structured and crystallizes in the tetragonal I4_1/amd space group. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to two equivalent Se(1) and two equivalent Se(2) atoms to form corner-sharing CeSe4 tetrahedra. In the second Ce site, Ce(2) is bonded to one Se(3), one Se(4), and two equivalent Se(1) atoms to form corner-sharing CeSe4 tetrahedra. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(2) atom. In the second Se site, Se(2) is bonded in a distorted bent 120 degrees geometry to two equivalent Ce(1) atoms. In the third Se site, Se(3) is bonded in a linear geometry to two equivalent Ce(2) atoms. In the fourth Se site, Se(4) is bonded in a linear geometry to two equivalent Ce(2) atoms. is represented by the CIF file [CIF]
data_CeSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.111
_cell_length_b   13.111
_cell_length_c   25.294
_cell_angle_alpha   105.021
_cell_angle_beta   105.021
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   4045.584
_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  0.434  0.184  0.250  1.0
  Ce  Ce1  1  0.434  0.566  0.250  1.0
  Ce  Ce2  1  0.184  0.434  0.750  1.0
  Ce  Ce3  1  0.184  0.816  0.750  1.0
  Ce  Ce4  1  0.816  0.184  0.250  1.0
  Ce  Ce5  1  0.816  0.566  0.250  1.0
  Ce  Ce6  1  0.566  0.434  0.750  1.0
  Ce  Ce7  1  0.566  0.816  0.750  1.0
  Ce  Ce8  1  0.986  0.943  0.387  1.0
  Ce  Ce9  1  0.943  0.986  0.887  1.0
  Ce  Ce10  1  0.943  0.400  0.887  1.0
  Ce  Ce11  1  0.400  0.943  0.387  1.0
  Ce  Ce12  1  0.014  0.057  0.613  1.0
  Ce  Ce13  1  0.057  0.014  0.113  1.0
  Ce  Ce14  1  0.057  0.600  0.113  1.0
  Ce  Ce15  1  0.600  0.057  0.613  1.0
  Se  Se16  1  0.437  0.096  0.337  1.0
  Se  Se17  1  0.437  0.741  0.337  1.0
  Se  Se18  1  0.096  0.437  0.837  1.0
  Se  Se19  1  0.096  0.899  0.837  1.0
  Se  Se20  1  0.899  0.096  0.337  1.0
  Se  Se21  1  0.899  0.741  0.337  1.0
  Se  Se22  1  0.741  0.437  0.837  1.0
  Se  Se23  1  0.741  0.899  0.837  1.0
  Se  Se24  1  0.563  0.904  0.663  1.0
  Se  Se25  1  0.563  0.259  0.663  1.0
  Se  Se26  1  0.904  0.563  0.163  1.0
  Se  Se27  1  0.904  0.101  0.163  1.0
  Se  Se28  1  0.101  0.904  0.663  1.0
  Se  Se29  1  0.101  0.259  0.663  1.0
  Se  Se30  1  0.259  0.563  0.163  1.0
  Se  Se31  1  0.259  0.101  0.163  1.0
  Se  Se32  1  0.132  0.604  0.709  1.0
  Se  Se33  1  0.604  0.132  0.209  1.0
  Se  Se34  1  0.604  0.577  0.209  1.0
  Se  Se35  1  0.577  0.604  0.709  1.0
  Se  Se36  1  0.868  0.396  0.291  1.0
  Se  Se37  1  0.396  0.868  0.791  1.0
  Se  Se38  1  0.396  0.423  0.791  1.0
  Se  Se39  1  0.423  0.396  0.291  1.0
  Se  Se40  1  0.190  0.940  0.381  1.0
  Se  Se41  1  0.940  0.190  0.881  1.0
  Se  Se42  1  0.810  0.060  0.619  1.0
  Se  Se43  1  0.060  0.810  0.119  1.0
  Se  Se44  1  0.000  0.000  0.500  1.0
  Se  Se45  1  0.000  0.000  0.000  1.0
  Se  Se46  1  0.000  0.500  0.000  1.0
  Se  Se47  1  0.500  0.000  0.500  1.0
[/CIF]
.