The crystal structure described by CeSe2 is quartz (beta)-like structured and crystallizes in the monoclinic C2/m space group. There are three 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(3), 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(6), one Se(7), and one Se(8) atom to form corner-sharing CeSe4 tetrahedra. There are eight inequivalent Se sites. In the first Se site, Se(4) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(3) atom. In the second Se site, Se(5) is bonded in a bent 150 degrees geometry to two equivalent Ce(2) atoms. In the third Se site, Se(6) is bonded in a bent 150 degrees geometry to one Ce(2) and one Ce(3) atom. In the fourth Se site, Se(7) is bonded in a bent 150 degrees geometry to one Ce(2) and one Ce(3) atom. In the fifth Se site, Se(8) 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 bent 150 degrees geometry to two equivalent Ce(1) atoms. In the seventh Se site, Se(2) is bonded in a bent 150 degrees geometry to two equivalent Ce(1) atoms. In the eighth Se site, Se(3) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(2) atom. is represented by the CIF file [CIF]
data_CeSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.635
_cell_length_b   16.645
_cell_length_c   16.645
_cell_angle_alpha   88.437
_cell_angle_beta   81.149
_cell_angle_gamma   81.149
_symmetry_Int_Tables_number   1
_cell_volume   3417.938
_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  0.956  0.785  0.009  1.0
  Ce  Ce1  1  0.956  0.009  0.785  1.0
  Ce  Ce2  1  0.044  0.215  0.991  1.0
  Ce  Ce3  1  0.044  0.991  0.215  1.0
  Ce  Ce4  1  0.350  0.654  0.878  1.0
  Ce  Ce5  1  0.350  0.878  0.654  1.0
  Ce  Ce6  1  0.650  0.346  0.122  1.0
  Ce  Ce7  1  0.650  0.122  0.346  1.0
  Ce  Ce8  1  0.588  0.668  0.107  1.0
  Ce  Ce9  1  0.588  0.107  0.668  1.0
  Ce  Ce10  1  0.412  0.332  0.893  1.0
  Ce  Ce11  1  0.412  0.893  0.332  1.0
  Se  Se12  1  0.000  0.859  0.141  1.0
  Se  Se13  1  0.000  0.141  0.859  1.0
  Se  Se14  1  0.894  0.901  0.901  1.0
  Se  Se15  1  0.106  0.099  0.099  1.0
  Se  Se16  1  0.136  0.687  0.939  1.0
  Se  Se17  1  0.136  0.939  0.687  1.0
  Se  Se18  1  0.864  0.313  0.061  1.0
  Se  Se19  1  0.864  0.061  0.313  1.0
  Se  Se20  1  0.793  0.696  0.056  1.0
  Se  Se21  1  0.793  0.056  0.696  1.0
  Se  Se22  1  0.207  0.304  0.944  1.0
  Se  Se23  1  0.207  0.944  0.304  1.0
  Se  Se24  1  0.387  0.735  0.735  1.0
  Se  Se25  1  0.613  0.265  0.265  1.0
  Se  Se26  1  0.410  0.492  0.854  1.0
  Se  Se27  1  0.410  0.854  0.492  1.0
  Se  Se28  1  0.590  0.508  0.146  1.0
  Se  Se29  1  0.590  0.146  0.508  1.0
  Se  Se30  1  0.467  0.706  0.985  1.0
  Se  Se31  1  0.467  0.985  0.706  1.0
  Se  Se32  1  0.533  0.294  0.015  1.0
  Se  Se33  1  0.533  0.015  0.294  1.0
  Se  Se34  1  0.500  0.761  0.239  1.0
  Se  Se35  1  0.500  0.239  0.761  1.0
[/CIF]
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The crystal structure described by CeSe2 is quartz (beta)-like structured and crystallizes in the monoclinic C2/m space group. There are three 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(3), 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(6), one Se(7), and one Se(8) atom to form corner-sharing CeSe4 tetrahedra. There are eight inequivalent Se sites. In the first Se site, Se(4) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(3) atom. In the second Se site, Se(5) is bonded in a bent 150 degrees geometry to two equivalent Ce(2) atoms. In the third Se site, Se(6) is bonded in a bent 150 degrees geometry to one Ce(2) and one Ce(3) atom. In the fourth Se site, Se(7) is bonded in a bent 150 degrees geometry to one Ce(2) and one Ce(3) atom. In the fifth Se site, Se(8) 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 bent 150 degrees geometry to two equivalent Ce(1) atoms. In the seventh Se site, Se(2) is bonded in a bent 150 degrees geometry to two equivalent Ce(1) atoms. In the eighth Se site, Se(3) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(2) atom. is represented by the CIF file [CIF]
data_CeSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.635
_cell_length_b   16.645
_cell_length_c   16.645
_cell_angle_alpha   88.437
_cell_angle_beta   81.149
_cell_angle_gamma   81.149
_symmetry_Int_Tables_number   1
_cell_volume   3417.938
_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  0.956  0.785  0.009  1.0
  Ce  Ce1  1  0.956  0.009  0.785  1.0
  Ce  Ce2  1  0.044  0.215  0.991  1.0
  Ce  Ce3  1  0.044  0.991  0.215  1.0
  Ce  Ce4  1  0.350  0.654  0.878  1.0
  Ce  Ce5  1  0.350  0.878  0.654  1.0
  Ce  Ce6  1  0.650  0.346  0.122  1.0
  Ce  Ce7  1  0.650  0.122  0.346  1.0
  Ce  Ce8  1  0.588  0.668  0.107  1.0
  Ce  Ce9  1  0.588  0.107  0.668  1.0
  Ce  Ce10  1  0.412  0.332  0.893  1.0
  Ce  Ce11  1  0.412  0.893  0.332  1.0
  Se  Se12  1  0.000  0.859  0.141  1.0
  Se  Se13  1  0.000  0.141  0.859  1.0
  Se  Se14  1  0.894  0.901  0.901  1.0
  Se  Se15  1  0.106  0.099  0.099  1.0
  Se  Se16  1  0.136  0.687  0.939  1.0
  Se  Se17  1  0.136  0.939  0.687  1.0
  Se  Se18  1  0.864  0.313  0.061  1.0
  Se  Se19  1  0.864  0.061  0.313  1.0
  Se  Se20  1  0.793  0.696  0.056  1.0
  Se  Se21  1  0.793  0.056  0.696  1.0
  Se  Se22  1  0.207  0.304  0.944  1.0
  Se  Se23  1  0.207  0.944  0.304  1.0
  Se  Se24  1  0.387  0.735  0.735  1.0
  Se  Se25  1  0.613  0.265  0.265  1.0
  Se  Se26  1  0.410  0.492  0.854  1.0
  Se  Se27  1  0.410  0.854  0.492  1.0
  Se  Se28  1  0.590  0.508  0.146  1.0
  Se  Se29  1  0.590  0.146  0.508  1.0
  Se  Se30  1  0.467  0.706  0.985  1.0
  Se  Se31  1  0.467  0.985  0.706  1.0
  Se  Se32  1  0.533  0.294  0.015  1.0
  Se  Se33  1  0.533  0.015  0.294  1.0
  Se  Se34  1  0.500  0.761  0.239  1.0
  Se  Se35  1  0.500  0.239  0.761  1.0
[/CIF]
.