The compound described by CeSe2 crystallizes in the hexagonal P622 space group. Ce(1) is bonded in a distorted see-saw-like geometry to one Se(1), one Se(2), one Se(3), and one Se(4) atom. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a water-like geometry to two equivalent Ce(1) atoms. In the second Se site, Se(2) is bonded in a bent 150 degrees geometry to two equivalent Ce(1) atoms. In the third Se site, Se(3) is bonded in a bent 120 degrees geometry to two equivalent Ce(1) atoms. In the fourth Se site, Se(4) is bonded in a linear geometry to two equivalent Ce(1) atoms. is represented by the CIF card [CIF]
data_CeSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.101
_cell_length_b   21.346
_cell_length_c   21.346
_cell_angle_alpha   120.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   2407.406
_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  0.174  0.478  0.131  1.0
  Ce  Ce1  1  0.174  0.653  0.522  1.0
  Ce  Ce2  1  0.174  0.869  0.347  1.0
  Ce  Ce3  1  0.174  0.522  0.869  1.0
  Ce  Ce4  1  0.174  0.347  0.478  1.0
  Ce  Ce5  1  0.174  0.131  0.653  1.0
  Ce  Ce6  1  0.826  0.347  0.869  1.0
  Ce  Ce7  1  0.826  0.131  0.478  1.0
  Ce  Ce8  1  0.826  0.522  0.653  1.0
  Ce  Ce9  1  0.826  0.653  0.131  1.0
  Ce  Ce10  1  0.826  0.869  0.522  1.0
  Ce  Ce11  1  0.826  0.478  0.347  1.0
  Se  Se12  1  1.000  0.217  0.609  1.0
  Se  Se13  1  1.000  0.391  0.783  1.0
  Se  Se14  1  1.000  0.391  0.609  1.0
  Se  Se15  1  1.000  0.783  0.391  1.0
  Se  Se16  1  1.000  0.609  0.217  1.0
  Se  Se17  1  1.000  0.609  0.391  1.0
  Se  Se18  1  0.000  1.000  0.383  1.0
  Se  Se19  1  0.000  0.383  0.000  1.0
  Se  Se20  1  0.000  0.617  0.617  1.0
  Se  Se21  1  0.000  0.000  0.617  1.0
  Se  Se22  1  0.000  0.617  1.000  1.0
  Se  Se23  1  0.000  0.383  0.383  1.0
  Se  Se24  1  0.000  0.209  0.419  1.0
  Se  Se25  1  0.000  0.209  0.791  1.0
  Se  Se26  1  0.000  0.581  0.791  1.0
  Se  Se27  1  0.000  0.791  0.581  1.0
  Se  Se28  1  0.000  0.791  0.209  1.0
  Se  Se29  1  0.000  0.419  0.209  1.0
  Se  Se30  1  0.500  0.112  0.556  1.0
  Se  Se31  1  0.500  0.444  0.888  1.0
  Se  Se32  1  0.500  0.444  0.556  1.0
  Se  Se33  1  0.500  0.888  0.444  1.0
  Se  Se34  1  0.500  0.556  0.112  1.0
  Se  Se35  1  0.500  0.556  0.444  1.0
[/CIF]
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The compound described by CeSe2 crystallizes in the hexagonal P622 space group. Ce(1) is bonded in a distorted see-saw-like geometry to one Se(1), one Se(2), one Se(3), and one Se(4) atom. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a water-like geometry to two equivalent Ce(1) atoms. In the second Se site, Se(2) is bonded in a bent 150 degrees geometry to two equivalent Ce(1) atoms. In the third Se site, Se(3) is bonded in a bent 120 degrees geometry to two equivalent Ce(1) atoms. In the fourth Se site, Se(4) is bonded in a linear geometry to two equivalent Ce(1) atoms. is represented by the CIF card [CIF]
data_CeSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.101
_cell_length_b   21.346
_cell_length_c   21.346
_cell_angle_alpha   120.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   2407.406
_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  0.174  0.478  0.131  1.0
  Ce  Ce1  1  0.174  0.653  0.522  1.0
  Ce  Ce2  1  0.174  0.869  0.347  1.0
  Ce  Ce3  1  0.174  0.522  0.869  1.0
  Ce  Ce4  1  0.174  0.347  0.478  1.0
  Ce  Ce5  1  0.174  0.131  0.653  1.0
  Ce  Ce6  1  0.826  0.347  0.869  1.0
  Ce  Ce7  1  0.826  0.131  0.478  1.0
  Ce  Ce8  1  0.826  0.522  0.653  1.0
  Ce  Ce9  1  0.826  0.653  0.131  1.0
  Ce  Ce10  1  0.826  0.869  0.522  1.0
  Ce  Ce11  1  0.826  0.478  0.347  1.0
  Se  Se12  1  1.000  0.217  0.609  1.0
  Se  Se13  1  1.000  0.391  0.783  1.0
  Se  Se14  1  1.000  0.391  0.609  1.0
  Se  Se15  1  1.000  0.783  0.391  1.0
  Se  Se16  1  1.000  0.609  0.217  1.0
  Se  Se17  1  1.000  0.609  0.391  1.0
  Se  Se18  1  0.000  1.000  0.383  1.0
  Se  Se19  1  0.000  0.383  0.000  1.0
  Se  Se20  1  0.000  0.617  0.617  1.0
  Se  Se21  1  0.000  0.000  0.617  1.0
  Se  Se22  1  0.000  0.617  1.000  1.0
  Se  Se23  1  0.000  0.383  0.383  1.0
  Se  Se24  1  0.000  0.209  0.419  1.0
  Se  Se25  1  0.000  0.209  0.791  1.0
  Se  Se26  1  0.000  0.581  0.791  1.0
  Se  Se27  1  0.000  0.791  0.581  1.0
  Se  Se28  1  0.000  0.791  0.209  1.0
  Se  Se29  1  0.000  0.419  0.209  1.0
  Se  Se30  1  0.500  0.112  0.556  1.0
  Se  Se31  1  0.500  0.444  0.888  1.0
  Se  Se32  1  0.500  0.444  0.556  1.0
  Se  Se33  1  0.500  0.888  0.444  1.0
  Se  Se34  1  0.500  0.556  0.112  1.0
  Se  Se35  1  0.500  0.556  0.444  1.0
[/CIF]
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