The compound described by CeSe2 is Low Tridymite-like structured and crystallizes in the monoclinic P2/c space group. There are five inequivalent Ce sites. In the first Ce site, 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. In the second Ce site, Ce(2) is bonded to one Se(1), one Se(5), one Se(6), and one Se(7) atom to form corner-sharing CeSe4 tetrahedra. In the third Ce site, Ce(3) is bonded to one Se(4), one Se(7), one Se(8), and one Se(9) atom to form corner-sharing CeSe4 tetrahedra. In the fourth Ce site, Ce(4) is bonded to one Se(10), one Se(3), one Se(5), and one Se(6) atom to form corner-sharing CeSe4 tetrahedra. In the fifth Ce site, Ce(5) is bonded to two equivalent Se(10) and two equivalent Se(8) atoms to form corner-sharing CeSe4 tetrahedra. There are ten inequivalent Se sites. In the first Se site, Se(5) is bonded in a linear geometry to one Ce(2) and one Ce(4) atom. In the second Se site, Se(6) is bonded in a bent 150 degrees geometry to one Ce(2) and one Ce(4) atom. In the third Se site, Se(7) is bonded in a bent 150 degrees geometry to one Ce(2) and one Ce(3) atom. In the fourth Se site, Se(8) is bonded in a bent 150 degrees geometry to one Ce(3) and one Ce(5) atom. In the fifth Se site, Se(9) is bonded in a bent 150 degrees geometry to two equivalent Ce(3) atoms. In the sixth Se site, Se(1) is bonded in a linear geometry to one Ce(1) and one Ce(2) atom. In the seventh Se site, Se(10) is bonded in a bent 150 degrees geometry to one Ce(4) and one Ce(5) atom. In the eighth Se site, Se(2) is bonded in a linear geometry to two equivalent Ce(1) atoms. In the ninth Se site, Se(3) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(4) atom. In the tenth Se site, Se(4) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(3) atom. is represented by the CIF card [CIF]
data_CeSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.481
_cell_length_b   14.900
_cell_length_c   26.537
_cell_angle_alpha   90.000
_cell_angle_beta   91.244
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   4933.981
_cell_formula_units_Z   18
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  0.555  0.824  0.491  1.0
  Ce  Ce1  1  0.945  0.824  0.009  1.0
  Ce  Ce2  1  0.445  0.176  0.509  1.0
  Ce  Ce3  1  0.055  0.176  0.991  1.0
  Ce  Ce4  1  0.754  0.398  0.444  1.0
  Ce  Ce5  1  0.746  0.398  0.056  1.0
  Ce  Ce6  1  0.246  0.602  0.556  1.0
  Ce  Ce7  1  0.254  0.602  0.944  1.0
  Ce  Ce8  1  0.890  0.648  0.179  1.0
  Ce  Ce9  1  0.610  0.648  0.321  1.0
  Ce  Ce10  1  0.110  0.352  0.821  1.0
  Ce  Ce11  1  0.390  0.352  0.679  1.0
  Ce  Ce12  1  0.148  0.347  0.421  1.0
  Ce  Ce13  1  0.352  0.347  0.079  1.0
  Ce  Ce14  1  0.852  0.653  0.579  1.0
  Ce  Ce15  1  0.648  0.653  0.921  1.0
  Ce  Ce16  1  0.750  0.496  0.750  1.0
  Ce  Ce17  1  0.250  0.504  0.250  1.0
  Se  Se18  1  0.399  0.721  0.529  1.0
  Se  Se19  1  0.101  0.721  0.971  1.0
  Se  Se20  1  0.601  0.279  0.471  1.0
  Se  Se21  1  0.899  0.279  0.029  1.0
  Se  Se22  1  0.500  0.000  0.500  1.0
  Se  Se23  1  0.000  0.000  0.000  1.0
  Se  Se24  1  0.737  0.798  0.546  1.0
  Se  Se25  1  0.763  0.798  0.954  1.0
  Se  Se26  1  0.263  0.202  0.454  1.0
  Se  Se27  1  0.237  0.202  0.046  1.0
  Se  Se28  1  0.586  0.775  0.394  1.0
  Se  Se29  1  0.914  0.775  0.106  1.0
  Se  Se30  1  0.414  0.225  0.606  1.0
  Se  Se31  1  0.086  0.225  0.894  1.0
  Se  Se32  1  0.797  0.510  0.522  1.0
  Se  Se33  1  0.703  0.510  0.978  1.0
  Se  Se34  1  0.203  0.490  0.478  1.0
  Se  Se35  1  0.297  0.490  0.022  1.0
  Se  Se36  1  0.937  0.308  0.424  1.0
  Se  Se37  1  0.563  0.308  0.076  1.0
  Se  Se38  1  0.063  0.692  0.576  1.0
  Se  Se39  1  0.437  0.692  0.924  1.0
  Se  Se40  1  0.684  0.495  0.364  1.0
  Se  Se41  1  0.816  0.495  0.136  1.0
  Se  Se42  1  0.316  0.505  0.636  1.0
  Se  Se43  1  0.184  0.505  0.864  1.0
  Se  Se44  1  0.082  0.612  0.224  1.0
  Se  Se45  1  0.418  0.612  0.276  1.0
  Se  Se46  1  0.918  0.388  0.776  1.0
  Se  Se47  1  0.582  0.388  0.724  1.0
  Se  Se48  1  0.750  0.699  0.250  1.0
  Se  Se49  1  0.250  0.301  0.750  1.0
  Se  Se50  1  0.198  0.392  0.326  1.0
  Se  Se51  1  0.302  0.392  0.174  1.0
  Se  Se52  1  0.802  0.608  0.674  1.0
  Se  Se53  1  0.698  0.608  0.826  1.0
[/CIF]
.
The compound described by CeSe2 is Low Tridymite-like structured and crystallizes in the monoclinic P2/c space group. There are five inequivalent Ce sites. In the first Ce site, 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. In the second Ce site, Ce(2) is bonded to one Se(1), one Se(5), one Se(6), and one Se(7) atom to form corner-sharing CeSe4 tetrahedra. In the third Ce site, Ce(3) is bonded to one Se(4), one Se(7), one Se(8), and one Se(9) atom to form corner-sharing CeSe4 tetrahedra. In the fourth Ce site, Ce(4) is bonded to one Se(10), one Se(3), one Se(5), and one Se(6) atom to form corner-sharing CeSe4 tetrahedra. In the fifth Ce site, Ce(5) is bonded to two equivalent Se(10) and two equivalent Se(8) atoms to form corner-sharing CeSe4 tetrahedra. There are ten inequivalent Se sites. In the first Se site, Se(5) is bonded in a linear geometry to one Ce(2) and one Ce(4) atom. In the second Se site, Se(6) is bonded in a bent 150 degrees geometry to one Ce(2) and one Ce(4) atom. In the third Se site, Se(7) is bonded in a bent 150 degrees geometry to one Ce(2) and one Ce(3) atom. In the fourth Se site, Se(8) is bonded in a bent 150 degrees geometry to one Ce(3) and one Ce(5) atom. In the fifth Se site, Se(9) is bonded in a bent 150 degrees geometry to two equivalent Ce(3) atoms. In the sixth Se site, Se(1) is bonded in a linear geometry to one Ce(1) and one Ce(2) atom. In the seventh Se site, Se(10) is bonded in a bent 150 degrees geometry to one Ce(4) and one Ce(5) atom. In the eighth Se site, Se(2) is bonded in a linear geometry to two equivalent Ce(1) atoms. In the ninth Se site, Se(3) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(4) atom. In the tenth Se site, Se(4) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(3) atom. is represented by the CIF card [CIF]
data_CeSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.481
_cell_length_b   14.900
_cell_length_c   26.537
_cell_angle_alpha   90.000
_cell_angle_beta   91.244
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   4933.981
_cell_formula_units_Z   18
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  0.555  0.824  0.491  1.0
  Ce  Ce1  1  0.945  0.824  0.009  1.0
  Ce  Ce2  1  0.445  0.176  0.509  1.0
  Ce  Ce3  1  0.055  0.176  0.991  1.0
  Ce  Ce4  1  0.754  0.398  0.444  1.0
  Ce  Ce5  1  0.746  0.398  0.056  1.0
  Ce  Ce6  1  0.246  0.602  0.556  1.0
  Ce  Ce7  1  0.254  0.602  0.944  1.0
  Ce  Ce8  1  0.890  0.648  0.179  1.0
  Ce  Ce9  1  0.610  0.648  0.321  1.0
  Ce  Ce10  1  0.110  0.352  0.821  1.0
  Ce  Ce11  1  0.390  0.352  0.679  1.0
  Ce  Ce12  1  0.148  0.347  0.421  1.0
  Ce  Ce13  1  0.352  0.347  0.079  1.0
  Ce  Ce14  1  0.852  0.653  0.579  1.0
  Ce  Ce15  1  0.648  0.653  0.921  1.0
  Ce  Ce16  1  0.750  0.496  0.750  1.0
  Ce  Ce17  1  0.250  0.504  0.250  1.0
  Se  Se18  1  0.399  0.721  0.529  1.0
  Se  Se19  1  0.101  0.721  0.971  1.0
  Se  Se20  1  0.601  0.279  0.471  1.0
  Se  Se21  1  0.899  0.279  0.029  1.0
  Se  Se22  1  0.500  0.000  0.500  1.0
  Se  Se23  1  0.000  0.000  0.000  1.0
  Se  Se24  1  0.737  0.798  0.546  1.0
  Se  Se25  1  0.763  0.798  0.954  1.0
  Se  Se26  1  0.263  0.202  0.454  1.0
  Se  Se27  1  0.237  0.202  0.046  1.0
  Se  Se28  1  0.586  0.775  0.394  1.0
  Se  Se29  1  0.914  0.775  0.106  1.0
  Se  Se30  1  0.414  0.225  0.606  1.0
  Se  Se31  1  0.086  0.225  0.894  1.0
  Se  Se32  1  0.797  0.510  0.522  1.0
  Se  Se33  1  0.703  0.510  0.978  1.0
  Se  Se34  1  0.203  0.490  0.478  1.0
  Se  Se35  1  0.297  0.490  0.022  1.0
  Se  Se36  1  0.937  0.308  0.424  1.0
  Se  Se37  1  0.563  0.308  0.076  1.0
  Se  Se38  1  0.063  0.692  0.576  1.0
  Se  Se39  1  0.437  0.692  0.924  1.0
  Se  Se40  1  0.684  0.495  0.364  1.0
  Se  Se41  1  0.816  0.495  0.136  1.0
  Se  Se42  1  0.316  0.505  0.636  1.0
  Se  Se43  1  0.184  0.505  0.864  1.0
  Se  Se44  1  0.082  0.612  0.224  1.0
  Se  Se45  1  0.418  0.612  0.276  1.0
  Se  Se46  1  0.918  0.388  0.776  1.0
  Se  Se47  1  0.582  0.388  0.724  1.0
  Se  Se48  1  0.750  0.699  0.250  1.0
  Se  Se49  1  0.250  0.301  0.750  1.0
  Se  Se50  1  0.198  0.392  0.326  1.0
  Se  Se51  1  0.302  0.392  0.174  1.0
  Se  Se52  1  0.802  0.608  0.674  1.0
  Se  Se53  1  0.698  0.608  0.826  1.0
[/CIF]
.