The crystal structure described by CeSe2 crystallizes in the triclinic P-1 space group. There are eight inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to one Se(15), one Se(2), one Se(7), and one Se(8) atom to form corner-sharing CeSe4 tetrahedra. In the second Ce site, Ce(2) is bonded to one Se(8), one Se(9), and two equivalent Se(4) atoms to form a mixture of edge and corner-sharing CeSe4 tetrahedra. In the third Ce site, Ce(3) is bonded to one Se(11), one Se(12), one Se(13), and one Se(16) atom to form corner-sharing CeSe4 tetrahedra. In the fourth Ce site, Ce(4) is bonded to one Se(12), one Se(14), one Se(3), and one Se(7) atom to form corner-sharing CeSe4 tetrahedra. In the fifth Ce site, Ce(5) is bonded to one Se(11), one Se(5), and two equivalent Se(1) atoms to form a mixture of edge and corner-sharing CeSe4 tetrahedra. In the sixth Ce site, Ce(6) is bonded to one Se(14), one Se(2), and two equivalent Se(10) atoms to form a mixture of edge and corner-sharing CeSe4 tetrahedra. In the seventh Ce site, Ce(7) is bonded to one Se(16), one Se(3), and two equivalent Se(6) atoms to form a mixture of edge and corner-sharing CeSe4 tetrahedra. In the eighth Ce site, Ce(8) is bonded to one Se(13), one Se(15), one Se(5), and one Se(9) atom to form corner-sharing CeSe4 tetrahedra. There are sixteen inequivalent Se sites. In the first Se site, Se(1) is bonded in a water-like geometry to two equivalent Ce(5) atoms. In the second Se site, Se(2) is bonded in a bent 120 degrees geometry to one Ce(1) and one Ce(6) atom. In the third Se site, Se(3) is bonded in a bent 120 degrees geometry to one Ce(4) and one Ce(7) atom. In the fourth Se site, Se(4) is bonded in an L-shaped geometry to two equivalent Ce(2) atoms. In the fifth Se site, Se(5) is bonded in a bent 120 degrees geometry to one Ce(5) and one Ce(8) atom. In the sixth Se site, Se(6) is bonded in an L-shaped geometry to two equivalent Ce(7) atoms. In the seventh Se site, Se(7) is bonded in a bent 120 degrees geometry to one Ce(1) and one Ce(4) atom. In the eighth Se site, Se(8) is bonded in a bent 120 degrees geometry to one Ce(1) and one Ce(2) atom. In the ninth Se site, Se(9) is bonded in a bent 120 degrees geometry to one Ce(2) and one Ce(8) atom. In the tenth Se site, Se(10) is bonded in a water-like geometry to two equivalent Ce(6) atoms. In the eleventh Se site, Se(11) is bonded in a bent 120 degrees geometry to one Ce(3) and one Ce(5) atom. In the twelfth Se site, Se(12) is bonded in a bent 120 degrees geometry to one Ce(3) and one Ce(4) atom. In the thirteenth Se site, Se(13) is bonded in a bent 120 degrees geometry to one Ce(3) and one Ce(8) atom. In the fourteenth Se site, Se(14) is bonded in a bent 120 degrees geometry to one Ce(4) and one Ce(6) atom. In the fifteenth Se site, Se(15) is bonded in a bent 120 degrees geometry to one Ce(1) and one Ce(8) atom. In the sixteenth Se site, Se(16) is bonded in a bent 120 degrees geometry to one Ce(3) and one Ce(7) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_CeSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.914
_cell_length_b   22.669
_cell_length_c   22.663
_cell_angle_alpha   88.438
_cell_angle_beta   83.872
_cell_angle_gamma   83.971
_symmetry_Int_Tables_number   1
_cell_volume   4527.837
_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  0.135  0.396  0.745  1.0
  Ce  Ce1  1  0.865  0.604  0.255  1.0
  Ce  Ce2  1  0.415  0.439  0.558  1.0
  Ce  Ce3  1  0.585  0.561  0.442  1.0
  Ce  Ce4  1  0.210  0.101  0.750  1.0
  Ce  Ce5  1  0.790  0.899  0.250  1.0
  Ce  Ce6  1  0.136  0.246  0.896  1.0
  Ce  Ce7  1  0.864  0.754  0.104  1.0
  Ce  Ce8  1  0.040  0.060  0.560  1.0
  Ce  Ce9  1  0.960  0.940  0.440  1.0
  Ce  Ce10  1  0.962  0.439  0.939  1.0
  Ce  Ce11  1  0.038  0.561  0.061  1.0
  Ce  Ce12  1  0.415  0.058  0.938  1.0
  Ce  Ce13  1  0.585  0.942  0.062  1.0
  Ce  Ce14  1  0.210  0.250  0.601  1.0
  Ce  Ce15  1  0.790  0.750  0.399  1.0
  Se  Se16  1  0.798  0.018  0.518  1.0
  Se  Se17  1  0.202  0.982  0.482  1.0
  Se  Se18  1  0.936  0.464  0.821  1.0
  Se  Se19  1  0.064  0.536  0.179  1.0
  Se  Se20  1  0.322  0.175  0.962  1.0
  Se  Se21  1  0.678  0.825  0.038  1.0
  Se  Se22  1  0.688  0.478  0.522  1.0
  Se  Se23  1  0.312  0.522  0.478  1.0
  Se  Se24  1  0.067  0.178  0.535  1.0
  Se  Se25  1  0.933  0.822  0.465  1.0
  Se  Se26  1  0.312  0.978  0.022  1.0
  Se  Se27  1  0.688  0.022  0.978  1.0
  Se  Se28  1  0.285  0.325  0.824  1.0
  Se  Se29  1  0.715  0.675  0.176  1.0
  Se  Se30  1  0.321  0.463  0.675  1.0
  Se  Se31  1  0.679  0.537  0.325  1.0
  Se  Se32  1  0.390  0.322  0.534  1.0
  Se  Se33  1  0.610  0.678  0.466  1.0
  Se  Se34  1  0.798  0.518  0.018  1.0
  Se  Se35  1  0.202  0.482  0.982  1.0
  Se  Se36  1  0.067  0.035  0.678  1.0
  Se  Se37  1  0.933  0.965  0.322  1.0
  Se  Se38  1  0.015  0.170  0.827  1.0
  Se  Se39  1  0.985  0.830  0.173  1.0
  Se  Se40  1  0.365  0.174  0.674  1.0
  Se  Se41  1  0.635  0.826  0.326  1.0
  Se  Se42  1  0.937  0.321  0.964  1.0
  Se  Se43  1  0.063  0.679  0.036  1.0
  Se  Se44  1  0.014  0.326  0.670  1.0
  Se  Se45  1  0.986  0.674  0.330  1.0
  Se  Se46  1  0.390  0.034  0.822  1.0
  Se  Se47  1  0.610  0.966  0.178  1.0
[/CIF]
.
The crystal structure described by CeSe2 crystallizes in the triclinic P-1 space group. There are eight inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to one Se(15), one Se(2), one Se(7), and one Se(8) atom to form corner-sharing CeSe4 tetrahedra. In the second Ce site, Ce(2) is bonded to one Se(8), one Se(9), and two equivalent Se(4) atoms to form a mixture of edge and corner-sharing CeSe4 tetrahedra. In the third Ce site, Ce(3) is bonded to one Se(11), one Se(12), one Se(13), and one Se(16) atom to form corner-sharing CeSe4 tetrahedra. In the fourth Ce site, Ce(4) is bonded to one Se(12), one Se(14), one Se(3), and one Se(7) atom to form corner-sharing CeSe4 tetrahedra. In the fifth Ce site, Ce(5) is bonded to one Se(11), one Se(5), and two equivalent Se(1) atoms to form a mixture of edge and corner-sharing CeSe4 tetrahedra. In the sixth Ce site, Ce(6) is bonded to one Se(14), one Se(2), and two equivalent Se(10) atoms to form a mixture of edge and corner-sharing CeSe4 tetrahedra. In the seventh Ce site, Ce(7) is bonded to one Se(16), one Se(3), and two equivalent Se(6) atoms to form a mixture of edge and corner-sharing CeSe4 tetrahedra. In the eighth Ce site, Ce(8) is bonded to one Se(13), one Se(15), one Se(5), and one Se(9) atom to form corner-sharing CeSe4 tetrahedra. There are sixteen inequivalent Se sites. In the first Se site, Se(1) is bonded in a water-like geometry to two equivalent Ce(5) atoms. In the second Se site, Se(2) is bonded in a bent 120 degrees geometry to one Ce(1) and one Ce(6) atom. In the third Se site, Se(3) is bonded in a bent 120 degrees geometry to one Ce(4) and one Ce(7) atom. In the fourth Se site, Se(4) is bonded in an L-shaped geometry to two equivalent Ce(2) atoms. In the fifth Se site, Se(5) is bonded in a bent 120 degrees geometry to one Ce(5) and one Ce(8) atom. In the sixth Se site, Se(6) is bonded in an L-shaped geometry to two equivalent Ce(7) atoms. In the seventh Se site, Se(7) is bonded in a bent 120 degrees geometry to one Ce(1) and one Ce(4) atom. In the eighth Se site, Se(8) is bonded in a bent 120 degrees geometry to one Ce(1) and one Ce(2) atom. In the ninth Se site, Se(9) is bonded in a bent 120 degrees geometry to one Ce(2) and one Ce(8) atom. In the tenth Se site, Se(10) is bonded in a water-like geometry to two equivalent Ce(6) atoms. In the eleventh Se site, Se(11) is bonded in a bent 120 degrees geometry to one Ce(3) and one Ce(5) atom. In the twelfth Se site, Se(12) is bonded in a bent 120 degrees geometry to one Ce(3) and one Ce(4) atom. In the thirteenth Se site, Se(13) is bonded in a bent 120 degrees geometry to one Ce(3) and one Ce(8) atom. In the fourteenth Se site, Se(14) is bonded in a bent 120 degrees geometry to one Ce(4) and one Ce(6) atom. In the fifteenth Se site, Se(15) is bonded in a bent 120 degrees geometry to one Ce(1) and one Ce(8) atom. In the sixteenth Se site, Se(16) is bonded in a bent 120 degrees geometry to one Ce(3) and one Ce(7) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_CeSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.914
_cell_length_b   22.669
_cell_length_c   22.663
_cell_angle_alpha   88.438
_cell_angle_beta   83.872
_cell_angle_gamma   83.971
_symmetry_Int_Tables_number   1
_cell_volume   4527.837
_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  0.135  0.396  0.745  1.0
  Ce  Ce1  1  0.865  0.604  0.255  1.0
  Ce  Ce2  1  0.415  0.439  0.558  1.0
  Ce  Ce3  1  0.585  0.561  0.442  1.0
  Ce  Ce4  1  0.210  0.101  0.750  1.0
  Ce  Ce5  1  0.790  0.899  0.250  1.0
  Ce  Ce6  1  0.136  0.246  0.896  1.0
  Ce  Ce7  1  0.864  0.754  0.104  1.0
  Ce  Ce8  1  0.040  0.060  0.560  1.0
  Ce  Ce9  1  0.960  0.940  0.440  1.0
  Ce  Ce10  1  0.962  0.439  0.939  1.0
  Ce  Ce11  1  0.038  0.561  0.061  1.0
  Ce  Ce12  1  0.415  0.058  0.938  1.0
  Ce  Ce13  1  0.585  0.942  0.062  1.0
  Ce  Ce14  1  0.210  0.250  0.601  1.0
  Ce  Ce15  1  0.790  0.750  0.399  1.0
  Se  Se16  1  0.798  0.018  0.518  1.0
  Se  Se17  1  0.202  0.982  0.482  1.0
  Se  Se18  1  0.936  0.464  0.821  1.0
  Se  Se19  1  0.064  0.536  0.179  1.0
  Se  Se20  1  0.322  0.175  0.962  1.0
  Se  Se21  1  0.678  0.825  0.038  1.0
  Se  Se22  1  0.688  0.478  0.522  1.0
  Se  Se23  1  0.312  0.522  0.478  1.0
  Se  Se24  1  0.067  0.178  0.535  1.0
  Se  Se25  1  0.933  0.822  0.465  1.0
  Se  Se26  1  0.312  0.978  0.022  1.0
  Se  Se27  1  0.688  0.022  0.978  1.0
  Se  Se28  1  0.285  0.325  0.824  1.0
  Se  Se29  1  0.715  0.675  0.176  1.0
  Se  Se30  1  0.321  0.463  0.675  1.0
  Se  Se31  1  0.679  0.537  0.325  1.0
  Se  Se32  1  0.390  0.322  0.534  1.0
  Se  Se33  1  0.610  0.678  0.466  1.0
  Se  Se34  1  0.798  0.518  0.018  1.0
  Se  Se35  1  0.202  0.482  0.982  1.0
  Se  Se36  1  0.067  0.035  0.678  1.0
  Se  Se37  1  0.933  0.965  0.322  1.0
  Se  Se38  1  0.015  0.170  0.827  1.0
  Se  Se39  1  0.985  0.830  0.173  1.0
  Se  Se40  1  0.365  0.174  0.674  1.0
  Se  Se41  1  0.635  0.826  0.326  1.0
  Se  Se42  1  0.937  0.321  0.964  1.0
  Se  Se43  1  0.063  0.679  0.036  1.0
  Se  Se44  1  0.014  0.326  0.670  1.0
  Se  Se45  1  0.986  0.674  0.330  1.0
  Se  Se46  1  0.390  0.034  0.822  1.0
  Se  Se47  1  0.610  0.966  0.178  1.0
[/CIF]
.