The structure described by CeCrSe2O crystallizes in the monoclinic C2/m space group. Ce(1) is bonded in a 3-coordinate geometry to three equivalent Se(1), three equivalent Se(2), and three equivalent O(1) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form CrSe6 octahedra that share corners with four equivalent Cr(2)Se4O2 octahedra and edges with two equivalent Cr(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 55°. In the second Cr site, Cr(2) is bonded to four equivalent Se(2) and two equivalent O(1) atoms to form distorted CrSe4O2 octahedra that share corners with four equivalent Cr(1)Se6 octahedra and edges with two equivalent Cr(2)Se4O2 octahedra. The corner-sharing octahedral tilt angles are 55°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a 5-coordinate geometry to three equivalent Ce(1) and two equivalent Cr(1) atoms. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to three equivalent Ce(1), one Cr(1), and two equivalent Cr(2) atoms. O(1) is bonded to three equivalent Ce(1) and one Cr(2) atom to form a mixture of corner and edge-sharing OCe3Cr tetrahedra. is represented by the CIF file [CIF]
data_CeCrSe2O
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.926
_cell_length_b   6.095
_cell_length_c   8.395
_cell_angle_alpha   90.459
_cell_angle_beta   90.003
_cell_angle_gamma   108.783
_symmetry_Int_Tables_number   1
_cell_volume   190.192
_cell_formula_units_Z   2
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  0.228  0.456  0.808  1.0
  Ce  Ce1  1  0.772  0.544  0.192  1.0
  Cr  Cr2  1  1.000  1.000  0.500  1.0
  Cr  Cr3  1  0.500  1.000  0.000  1.0
  Se  Se4  1  0.355  0.709  0.464  1.0
  Se  Se5  1  0.052  0.105  0.203  1.0
  Se  Se6  1  0.948  0.895  0.797  1.0
  Se  Se7  1  0.645  0.291  0.536  1.0
  O  O8  1  0.672  0.345  0.937  1.0
  O  O9  1  0.328  0.655  0.063  1.0
[/CIF]
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The structure described by CeCrSe2O crystallizes in the monoclinic C2/m space group. Ce(1) is bonded in a 3-coordinate geometry to three equivalent Se(1), three equivalent Se(2), and three equivalent O(1) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form CrSe6 octahedra that share corners with four equivalent Cr(2)Se4O2 octahedra and edges with two equivalent Cr(1)Se6 octahedra. The corner-sharing octahedral tilt angles are 55°. In the second Cr site, Cr(2) is bonded to four equivalent Se(2) and two equivalent O(1) atoms to form distorted CrSe4O2 octahedra that share corners with four equivalent Cr(1)Se6 octahedra and edges with two equivalent Cr(2)Se4O2 octahedra. The corner-sharing octahedral tilt angles are 55°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a 5-coordinate geometry to three equivalent Ce(1) and two equivalent Cr(1) atoms. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to three equivalent Ce(1), one Cr(1), and two equivalent Cr(2) atoms. O(1) is bonded to three equivalent Ce(1) and one Cr(2) atom to form a mixture of corner and edge-sharing OCe3Cr tetrahedra. is represented by the CIF file [CIF]
data_CeCrSe2O
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.926
_cell_length_b   6.095
_cell_length_c   8.395
_cell_angle_alpha   90.459
_cell_angle_beta   90.003
_cell_angle_gamma   108.783
_symmetry_Int_Tables_number   1
_cell_volume   190.192
_cell_formula_units_Z   2
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  0.228  0.456  0.808  1.0
  Ce  Ce1  1  0.772  0.544  0.192  1.0
  Cr  Cr2  1  1.000  1.000  0.500  1.0
  Cr  Cr3  1  0.500  1.000  0.000  1.0
  Se  Se4  1  0.355  0.709  0.464  1.0
  Se  Se5  1  0.052  0.105  0.203  1.0
  Se  Se6  1  0.948  0.895  0.797  1.0
  Se  Se7  1  0.645  0.291  0.536  1.0
  O  O8  1  0.672  0.345  0.937  1.0
  O  O9  1  0.328  0.655  0.063  1.0
[/CIF]
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