The material structure described by CeSe2 is Keatite-like structured and crystallizes in the orthorhombic Cmc2_1 space group. There are four inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to one Se(2), one Se(3), and two equivalent Se(1) atoms to form corner-sharing CeSe4 tetrahedra. In the second Ce site, Ce(2) is bonded to one Se(2), one Se(5), and two equivalent Se(4) atoms to form corner-sharing CeSe4 tetrahedra. In the third Ce site, Ce(3) is bonded to one Se(6), one Se(7), and two equivalent Se(5) atoms to form corner-sharing CeSe4 tetrahedra. In the fourth Ce site, Ce(4) is bonded to one Se(6), one Se(7), and two equivalent Se(3) atoms to form corner-sharing CeSe4 tetrahedra. There are seven inequivalent Se sites. In the first Se site, Se(3) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(4) atom. In the second Se site, Se(4) is bonded in a linear geometry to two equivalent Ce(2) atoms. In the third Se site, Se(5) is bonded in a bent 150 degrees geometry to one Ce(2) and one Ce(3) atom. In the fourth Se site, Se(6) is bonded in a bent 150 degrees geometry to one Ce(3) and one Ce(4) atom. In the fifth Se site, Se(7) is bonded in a bent 150 degrees geometry to one Ce(3) and one Ce(4) atom. 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 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   8.714
_cell_length_b   18.924
_cell_length_c   18.924
_cell_angle_alpha   103.419
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   3035.472
_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  0.240  0.763  0.661  1.0
  Ce  Ce1  1  0.240  0.339  0.237  1.0
  Ce  Ce2  1  0.740  0.237  0.339  1.0
  Ce  Ce3  1  0.740  0.661  0.763  1.0
  Ce  Ce4  1  0.192  0.009  0.584  1.0
  Ce  Ce5  1  0.192  0.416  0.991  1.0
  Ce  Ce6  1  0.692  0.991  0.416  1.0
  Ce  Ce7  1  0.692  0.584  0.009  1.0
  Ce  Ce8  1  0.667  0.715  0.285  1.0
  Ce  Ce9  1  0.167  0.285  0.715  1.0
  Ce  Ce10  1  0.175  0.615  0.385  1.0
  Ce  Ce11  1  0.675  0.385  0.615  1.0
  Se  Se12  1  0.011  0.726  0.744  1.0
  Se  Se13  1  0.011  0.256  0.274  1.0
  Se  Se14  1  0.511  0.274  0.256  1.0
  Se  Se15  1  0.511  0.744  0.726  1.0
  Se  Se16  1  0.193  0.905  0.660  1.0
  Se  Se17  1  0.193  0.340  0.095  1.0
  Se  Se18  1  0.693  0.095  0.340  1.0
  Se  Se19  1  0.693  0.660  0.905  1.0
  Se  Se20  1  0.220  0.665  0.530  1.0
  Se  Se21  1  0.220  0.470  0.335  1.0
  Se  Se22  1  0.720  0.335  0.470  1.0
  Se  Se23  1  0.720  0.530  0.665  1.0
  Se  Se24  1  0.964  0.000  0.485  1.0
  Se  Se25  1  0.964  0.515  1.000  1.0
  Se  Se26  1  0.464  1.000  0.515  1.0
  Se  Se27  1  0.464  0.485  0.000  1.0
  Se  Se28  1  0.705  0.860  0.322  1.0
  Se  Se29  1  0.705  0.678  0.140  1.0
  Se  Se30  1  0.205  0.140  0.678  1.0
  Se  Se31  1  0.205  0.322  0.860  1.0
  Se  Se32  1  0.886  0.650  0.350  1.0
  Se  Se33  1  0.386  0.350  0.650  1.0
  Se  Se34  1  0.371  0.686  0.314  1.0
  Se  Se35  1  0.871  0.314  0.686  1.0
[/CIF]
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The material structure described by CeSe2 is Keatite-like structured and crystallizes in the orthorhombic Cmc2_1 space group. There are four inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to one Se(2), one Se(3), and two equivalent Se(1) atoms to form corner-sharing CeSe4 tetrahedra. In the second Ce site, Ce(2) is bonded to one Se(2), one Se(5), and two equivalent Se(4) atoms to form corner-sharing CeSe4 tetrahedra. In the third Ce site, Ce(3) is bonded to one Se(6), one Se(7), and two equivalent Se(5) atoms to form corner-sharing CeSe4 tetrahedra. In the fourth Ce site, Ce(4) is bonded to one Se(6), one Se(7), and two equivalent Se(3) atoms to form corner-sharing CeSe4 tetrahedra. There are seven inequivalent Se sites. In the first Se site, Se(3) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(4) atom. In the second Se site, Se(4) is bonded in a linear geometry to two equivalent Ce(2) atoms. In the third Se site, Se(5) is bonded in a bent 150 degrees geometry to one Ce(2) and one Ce(3) atom. In the fourth Se site, Se(6) is bonded in a bent 150 degrees geometry to one Ce(3) and one Ce(4) atom. In the fifth Se site, Se(7) is bonded in a bent 150 degrees geometry to one Ce(3) and one Ce(4) atom. 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 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   8.714
_cell_length_b   18.924
_cell_length_c   18.924
_cell_angle_alpha   103.419
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   3035.472
_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  0.240  0.763  0.661  1.0
  Ce  Ce1  1  0.240  0.339  0.237  1.0
  Ce  Ce2  1  0.740  0.237  0.339  1.0
  Ce  Ce3  1  0.740  0.661  0.763  1.0
  Ce  Ce4  1  0.192  0.009  0.584  1.0
  Ce  Ce5  1  0.192  0.416  0.991  1.0
  Ce  Ce6  1  0.692  0.991  0.416  1.0
  Ce  Ce7  1  0.692  0.584  0.009  1.0
  Ce  Ce8  1  0.667  0.715  0.285  1.0
  Ce  Ce9  1  0.167  0.285  0.715  1.0
  Ce  Ce10  1  0.175  0.615  0.385  1.0
  Ce  Ce11  1  0.675  0.385  0.615  1.0
  Se  Se12  1  0.011  0.726  0.744  1.0
  Se  Se13  1  0.011  0.256  0.274  1.0
  Se  Se14  1  0.511  0.274  0.256  1.0
  Se  Se15  1  0.511  0.744  0.726  1.0
  Se  Se16  1  0.193  0.905  0.660  1.0
  Se  Se17  1  0.193  0.340  0.095  1.0
  Se  Se18  1  0.693  0.095  0.340  1.0
  Se  Se19  1  0.693  0.660  0.905  1.0
  Se  Se20  1  0.220  0.665  0.530  1.0
  Se  Se21  1  0.220  0.470  0.335  1.0
  Se  Se22  1  0.720  0.335  0.470  1.0
  Se  Se23  1  0.720  0.530  0.665  1.0
  Se  Se24  1  0.964  0.000  0.485  1.0
  Se  Se25  1  0.964  0.515  1.000  1.0
  Se  Se26  1  0.464  1.000  0.515  1.0
  Se  Se27  1  0.464  0.485  0.000  1.0
  Se  Se28  1  0.705  0.860  0.322  1.0
  Se  Se29  1  0.705  0.678  0.140  1.0
  Se  Se30  1  0.205  0.140  0.678  1.0
  Se  Se31  1  0.205  0.322  0.860  1.0
  Se  Se32  1  0.886  0.650  0.350  1.0
  Se  Se33  1  0.386  0.350  0.650  1.0
  Se  Se34  1  0.371  0.686  0.314  1.0
  Se  Se35  1  0.871  0.314  0.686  1.0
[/CIF]
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