The structure described by CeSe2 crystallizes in the trigonal R3 space group. There are four inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to one Se(1), one Se(3), one Se(5), and one Se(7) atom to form distorted corner-sharing CeSe4 tetrahedra. In the second Ce site, Ce(2) is bonded to one Se(2), one Se(4), one Se(6), and one Se(8) atom to form distorted corner-sharing CeSe4 tetrahedra. In the third Ce site, Ce(3) is bonded to one Se(2), one Se(4), one Se(6), and one Se(7) atom to form distorted corner-sharing CeSe4 tetrahedra. In the fourth Ce site, Ce(4) is bonded to one Se(1), one Se(3), one Se(5), and one Se(8) atom to form distorted corner-sharing CeSe4 tetrahedra. There are eight inequivalent Se sites. In the first Se site, Se(1) is bonded in a water-like geometry to one Ce(1) and one Ce(4) atom. In the second Se site, Se(2) is bonded in a water-like geometry to one Ce(2) and one Ce(3) atom. In the third Se site, Se(3) is bonded in a linear geometry to one Ce(1) and one Ce(4) atom. In the fourth Se site, Se(4) is bonded in a linear geometry to one Ce(2) and one Ce(3) atom. In the fifth Se site, Se(5) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(4) atom. In the sixth Se site, Se(6) is bonded in a bent 150 degrees geometry to one Ce(2) and one Ce(3) atom. In the seventh Se site, Se(7) is bonded in a linear geometry to one Ce(1) and one Ce(3) atom. In the eighth Se site, Se(8) is bonded in a linear geometry to one Ce(2) and one Ce(4) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_CeSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.649
_cell_length_b   18.394
_cell_length_c   18.394
_cell_angle_alpha   114.909
_cell_angle_beta   103.251
_cell_angle_gamma   103.251
_symmetry_Int_Tables_number   1
_cell_volume   3511.778
_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  0.874  0.826  0.402  1.0
  Ce  Ce1  1  0.472  0.598  0.425  1.0
  Ce  Ce2  1  0.048  0.575  0.174  1.0
  Ce  Ce3  1  0.548  0.174  0.575  1.0
  Ce  Ce4  1  0.972  0.425  0.598  1.0
  Ce  Ce5  1  0.374  0.402  0.826  1.0
  Ce  Ce6  1  0.126  0.174  0.598  1.0
  Ce  Ce7  1  0.528  0.402  0.575  1.0
  Ce  Ce8  1  0.952  0.425  0.826  1.0
  Ce  Ce9  1  0.452  0.827  0.425  1.0
  Ce  Ce10  1  0.027  0.575  0.402  1.0
  Ce  Ce11  1  0.625  0.598  0.173  1.0
  Se  Se12  1  0.750  0.769  0.231  1.0
  Se  Se13  1  0.519  0.769  0.537  1.0
  Se  Se14  1  0.981  0.463  0.231  1.0
  Se  Se15  1  0.481  0.231  0.463  1.0
  Se  Se16  1  0.019  0.537  0.769  1.0
  Se  Se17  1  0.250  0.231  0.769  1.0
  Se  Se18  1  0.250  0.586  0.414  1.0
  Se  Se19  1  0.837  0.586  0.173  1.0
  Se  Se20  1  0.664  0.827  0.414  1.0
  Se  Se21  1  0.163  0.414  0.827  1.0
  Se  Se22  1  0.336  0.173  0.586  1.0
  Se  Se23  1  0.750  0.414  0.586  1.0
  Se  Se24  1  0.530  0.560  0.280  1.0
  Se  Se25  1  0.250  0.720  0.280  1.0
  Se  Se26  1  0.970  0.720  0.440  1.0
  Se  Se27  1  0.470  0.440  0.720  1.0
  Se  Se28  1  0.750  0.280  0.720  1.0
  Se  Se29  1  0.030  0.280  0.560  1.0
  Se  Se30  1  1.000  1.000  0.500  1.0
  Se  Se31  1  0.500  0.500  0.500  1.0
  Se  Se32  1  0.000  0.500  0.000  1.0
  Se  Se33  1  0.500  1.000  0.500  1.0
  Se  Se34  1  0.000  0.500  0.500  1.0
  Se  Se35  1  0.500  0.500  0.000  1.0
[/CIF]
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The structure described by CeSe2 crystallizes in the trigonal R3 space group. There are four inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to one Se(1), one Se(3), one Se(5), and one Se(7) atom to form distorted corner-sharing CeSe4 tetrahedra. In the second Ce site, Ce(2) is bonded to one Se(2), one Se(4), one Se(6), and one Se(8) atom to form distorted corner-sharing CeSe4 tetrahedra. In the third Ce site, Ce(3) is bonded to one Se(2), one Se(4), one Se(6), and one Se(7) atom to form distorted corner-sharing CeSe4 tetrahedra. In the fourth Ce site, Ce(4) is bonded to one Se(1), one Se(3), one Se(5), and one Se(8) atom to form distorted corner-sharing CeSe4 tetrahedra. There are eight inequivalent Se sites. In the first Se site, Se(1) is bonded in a water-like geometry to one Ce(1) and one Ce(4) atom. In the second Se site, Se(2) is bonded in a water-like geometry to one Ce(2) and one Ce(3) atom. In the third Se site, Se(3) is bonded in a linear geometry to one Ce(1) and one Ce(4) atom. In the fourth Se site, Se(4) is bonded in a linear geometry to one Ce(2) and one Ce(3) atom. In the fifth Se site, Se(5) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(4) atom. In the sixth Se site, Se(6) is bonded in a bent 150 degrees geometry to one Ce(2) and one Ce(3) atom. In the seventh Se site, Se(7) is bonded in a linear geometry to one Ce(1) and one Ce(3) atom. In the eighth Se site, Se(8) is bonded in a linear geometry to one Ce(2) and one Ce(4) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_CeSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.649
_cell_length_b   18.394
_cell_length_c   18.394
_cell_angle_alpha   114.909
_cell_angle_beta   103.251
_cell_angle_gamma   103.251
_symmetry_Int_Tables_number   1
_cell_volume   3511.778
_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  0.874  0.826  0.402  1.0
  Ce  Ce1  1  0.472  0.598  0.425  1.0
  Ce  Ce2  1  0.048  0.575  0.174  1.0
  Ce  Ce3  1  0.548  0.174  0.575  1.0
  Ce  Ce4  1  0.972  0.425  0.598  1.0
  Ce  Ce5  1  0.374  0.402  0.826  1.0
  Ce  Ce6  1  0.126  0.174  0.598  1.0
  Ce  Ce7  1  0.528  0.402  0.575  1.0
  Ce  Ce8  1  0.952  0.425  0.826  1.0
  Ce  Ce9  1  0.452  0.827  0.425  1.0
  Ce  Ce10  1  0.027  0.575  0.402  1.0
  Ce  Ce11  1  0.625  0.598  0.173  1.0
  Se  Se12  1  0.750  0.769  0.231  1.0
  Se  Se13  1  0.519  0.769  0.537  1.0
  Se  Se14  1  0.981  0.463  0.231  1.0
  Se  Se15  1  0.481  0.231  0.463  1.0
  Se  Se16  1  0.019  0.537  0.769  1.0
  Se  Se17  1  0.250  0.231  0.769  1.0
  Se  Se18  1  0.250  0.586  0.414  1.0
  Se  Se19  1  0.837  0.586  0.173  1.0
  Se  Se20  1  0.664  0.827  0.414  1.0
  Se  Se21  1  0.163  0.414  0.827  1.0
  Se  Se22  1  0.336  0.173  0.586  1.0
  Se  Se23  1  0.750  0.414  0.586  1.0
  Se  Se24  1  0.530  0.560  0.280  1.0
  Se  Se25  1  0.250  0.720  0.280  1.0
  Se  Se26  1  0.970  0.720  0.440  1.0
  Se  Se27  1  0.470  0.440  0.720  1.0
  Se  Se28  1  0.750  0.280  0.720  1.0
  Se  Se29  1  0.030  0.280  0.560  1.0
  Se  Se30  1  1.000  1.000  0.500  1.0
  Se  Se31  1  0.500  0.500  0.500  1.0
  Se  Se32  1  0.000  0.500  0.000  1.0
  Se  Se33  1  0.500  1.000  0.500  1.0
  Se  Se34  1  0.000  0.500  0.500  1.0
  Se  Se35  1  0.500  0.500  0.000  1.0
[/CIF]
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