The material described by Ce2O2FeSe2 crystallizes in the orthorhombic Cmc2_1 space group. There are four inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 4-coordinate geometry to two equivalent Se(1), two equivalent Se(4), one O(2), one O(3), and two equivalent O(1) atoms. In the second Ce site, Ce(2) is bonded in a 4-coordinate geometry to two equivalent Se(2), two equivalent Se(4), one O(1), one O(4), and two equivalent O(2) atoms. In the third Ce site, Ce(3) is bonded in a 3-coordinate geometry to one Se(3), two equivalent Se(1), two equivalent Se(2), one O(1), and two equivalent O(3) atoms. In the fourth Ce site, Ce(4) is bonded in a 3-coordinate geometry to one Se(3), two equivalent Se(1), two equivalent Se(2), one O(2), and two equivalent O(4) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted linear geometry to two equivalent Se(3), two equivalent Se(4), one O(3), and one O(4) atom. In the second Fe site, Fe(2) is bonded to one Se(1), one Se(4), and two equivalent Se(3) atoms to form distorted corner-sharing FeSe4 tetrahedra. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a 7-coordinate geometry to two equivalent Ce(1), two equivalent Ce(3), two equivalent Ce(4), and one Fe(2) atom. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to two equivalent Ce(2), two equivalent Ce(3), and two equivalent Ce(4) atoms. In the third Se site, Se(3) is bonded in a 6-coordinate geometry to one Ce(3), one Ce(4), two equivalent Fe(1), and two equivalent Fe(2) atoms. In the fourth Se site, Se(4) is bonded in a 7-coordinate geometry to two equivalent Ce(1), two equivalent Ce(2), one Fe(2), and two equivalent Fe(1) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Ce(2), one Ce(3), and two equivalent Ce(1) atoms to form OCe4 tetrahedra that share  a cornercorner with one O(4)Ce3Fe tetrahedra, corners with two equivalent O(1)Ce4 tetrahedra, edges with two equivalent O(3)Ce3Fe tetrahedra, and edges with two equivalent O(2)Ce4 tetrahedra. In the second O site, O(2) is bonded to one Ce(1), one Ce(4), and two equivalent Ce(2) atoms to form OCe4 tetrahedra that share  a cornercorner with one O(3)Ce3Fe tetrahedra, corners with two equivalent O(2)Ce4 tetrahedra, edges with two equivalent O(4)Ce3Fe tetrahedra, and edges with two equivalent O(1)Ce4 tetrahedra. In the third O site, O(3) is bonded to one Ce(1), two equivalent Ce(3), and one Fe(1) atom to form OCe3Fe tetrahedra that share  a cornercorner with one O(4)Ce3Fe tetrahedra,  a cornercorner with one O(2)Ce4 tetrahedra, corners with two equivalent O(3)Ce3Fe tetrahedra, and edges with two equivalent O(1)Ce4 tetrahedra. In the fourth O site, O(4) is bonded to one Ce(2), two equivalent Ce(4), and one Fe(1) atom to form OCe3Fe tetrahedra that share  a cornercorner with one O(3)Ce3Fe tetrahedra,  a cornercorner with one O(1)Ce4 tetrahedra, corners with two equivalent O(4)Ce3Fe tetrahedra, and edges with two equivalent O(2)Ce4 tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ce2Fe(SeO)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.443
_cell_length_b   8.443
_cell_length_c   17.290
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   152.816
_symmetry_Int_Tables_number   1
_cell_volume   563.012
_cell_formula_units_Z   4
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  0.768  0.232  0.590  1.0
  Ce  Ce1  1  0.229  0.771  0.408  1.0
  Ce  Ce2  1  0.771  0.229  0.908  1.0
  Ce  Ce3  1  0.232  0.768  0.090  1.0
  Ce  Ce4  1  0.074  0.925  0.581  1.0
  Ce  Ce5  1  0.926  0.074  0.417  1.0
  Ce  Ce6  1  0.074  0.926  0.917  1.0
  Ce  Ce7  1  0.925  0.074  0.081  1.0
  Fe  Fe8  1  0.633  0.367  0.750  1.0
  Fe  Fe9  1  0.367  0.633  0.250  1.0
  Fe  Fe10  1  0.412  0.588  0.723  1.0
  Fe  Fe11  1  0.588  0.412  0.223  1.0
  Se  Se12  1  0.420  0.580  0.571  1.0
  Se  Se13  1  0.579  0.421  0.433  1.0
  Se  Se14  1  0.421  0.579  0.933  1.0
  Se  Se15  1  0.580  0.420  0.071  1.0
  Se  Se16  1  0.006  0.994  0.751  1.0
  Se  Se17  1  0.994  0.006  0.251  1.0
  Se  Se18  1  0.259  0.741  0.751  1.0
  Se  Se19  1  0.741  0.259  0.251  1.0
  O  O20  1  0.211  0.789  0.545  1.0
  O  O21  1  0.790  0.210  0.455  1.0
  O  O22  1  0.210  0.790  0.955  1.0
  O  O23  1  0.789  0.211  0.045  1.0
  O  O24  1  0.630  0.370  0.635  1.0
  O  O25  1  0.371  0.629  0.365  1.0
  O  O26  1  0.629  0.371  0.865  1.0
  O  O27  1  0.370  0.630  0.135  1.0
[/CIF]
.
The material described by Ce2O2FeSe2 crystallizes in the orthorhombic Cmc2_1 space group. There are four inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 4-coordinate geometry to two equivalent Se(1), two equivalent Se(4), one O(2), one O(3), and two equivalent O(1) atoms. In the second Ce site, Ce(2) is bonded in a 4-coordinate geometry to two equivalent Se(2), two equivalent Se(4), one O(1), one O(4), and two equivalent O(2) atoms. In the third Ce site, Ce(3) is bonded in a 3-coordinate geometry to one Se(3), two equivalent Se(1), two equivalent Se(2), one O(1), and two equivalent O(3) atoms. In the fourth Ce site, Ce(4) is bonded in a 3-coordinate geometry to one Se(3), two equivalent Se(1), two equivalent Se(2), one O(2), and two equivalent O(4) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted linear geometry to two equivalent Se(3), two equivalent Se(4), one O(3), and one O(4) atom. In the second Fe site, Fe(2) is bonded to one Se(1), one Se(4), and two equivalent Se(3) atoms to form distorted corner-sharing FeSe4 tetrahedra. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a 7-coordinate geometry to two equivalent Ce(1), two equivalent Ce(3), two equivalent Ce(4), and one Fe(2) atom. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to two equivalent Ce(2), two equivalent Ce(3), and two equivalent Ce(4) atoms. In the third Se site, Se(3) is bonded in a 6-coordinate geometry to one Ce(3), one Ce(4), two equivalent Fe(1), and two equivalent Fe(2) atoms. In the fourth Se site, Se(4) is bonded in a 7-coordinate geometry to two equivalent Ce(1), two equivalent Ce(2), one Fe(2), and two equivalent Fe(1) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Ce(2), one Ce(3), and two equivalent Ce(1) atoms to form OCe4 tetrahedra that share  a cornercorner with one O(4)Ce3Fe tetrahedra, corners with two equivalent O(1)Ce4 tetrahedra, edges with two equivalent O(3)Ce3Fe tetrahedra, and edges with two equivalent O(2)Ce4 tetrahedra. In the second O site, O(2) is bonded to one Ce(1), one Ce(4), and two equivalent Ce(2) atoms to form OCe4 tetrahedra that share  a cornercorner with one O(3)Ce3Fe tetrahedra, corners with two equivalent O(2)Ce4 tetrahedra, edges with two equivalent O(4)Ce3Fe tetrahedra, and edges with two equivalent O(1)Ce4 tetrahedra. In the third O site, O(3) is bonded to one Ce(1), two equivalent Ce(3), and one Fe(1) atom to form OCe3Fe tetrahedra that share  a cornercorner with one O(4)Ce3Fe tetrahedra,  a cornercorner with one O(2)Ce4 tetrahedra, corners with two equivalent O(3)Ce3Fe tetrahedra, and edges with two equivalent O(1)Ce4 tetrahedra. In the fourth O site, O(4) is bonded to one Ce(2), two equivalent Ce(4), and one Fe(1) atom to form OCe3Fe tetrahedra that share  a cornercorner with one O(3)Ce3Fe tetrahedra,  a cornercorner with one O(1)Ce4 tetrahedra, corners with two equivalent O(4)Ce3Fe tetrahedra, and edges with two equivalent O(2)Ce4 tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ce2Fe(SeO)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.443
_cell_length_b   8.443
_cell_length_c   17.290
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   152.816
_symmetry_Int_Tables_number   1
_cell_volume   563.012
_cell_formula_units_Z   4
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  0.768  0.232  0.590  1.0
  Ce  Ce1  1  0.229  0.771  0.408  1.0
  Ce  Ce2  1  0.771  0.229  0.908  1.0
  Ce  Ce3  1  0.232  0.768  0.090  1.0
  Ce  Ce4  1  0.074  0.925  0.581  1.0
  Ce  Ce5  1  0.926  0.074  0.417  1.0
  Ce  Ce6  1  0.074  0.926  0.917  1.0
  Ce  Ce7  1  0.925  0.074  0.081  1.0
  Fe  Fe8  1  0.633  0.367  0.750  1.0
  Fe  Fe9  1  0.367  0.633  0.250  1.0
  Fe  Fe10  1  0.412  0.588  0.723  1.0
  Fe  Fe11  1  0.588  0.412  0.223  1.0
  Se  Se12  1  0.420  0.580  0.571  1.0
  Se  Se13  1  0.579  0.421  0.433  1.0
  Se  Se14  1  0.421  0.579  0.933  1.0
  Se  Se15  1  0.580  0.420  0.071  1.0
  Se  Se16  1  0.006  0.994  0.751  1.0
  Se  Se17  1  0.994  0.006  0.251  1.0
  Se  Se18  1  0.259  0.741  0.751  1.0
  Se  Se19  1  0.741  0.259  0.251  1.0
  O  O20  1  0.211  0.789  0.545  1.0
  O  O21  1  0.790  0.210  0.455  1.0
  O  O22  1  0.210  0.790  0.955  1.0
  O  O23  1  0.789  0.211  0.045  1.0
  O  O24  1  0.630  0.370  0.635  1.0
  O  O25  1  0.371  0.629  0.365  1.0
  O  O26  1  0.629  0.371  0.865  1.0
  O  O27  1  0.370  0.630  0.135  1.0
[/CIF]
.