The compound described by Ce3NSe2O crystallizes in the monoclinic Cm space group. There are nine inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 4-coordinate geometry to two equivalent N(3), one Se(3), two equivalent Se(2), one O(1), and one O(2) atom. In the second Ce site, Ce(2) is bonded in a 4-coordinate geometry to one Se(4), two equivalent Se(1), one O(1), one O(2), and two equivalent O(3) atoms. In the third Ce site, Ce(3) is bonded in a 3-coordinate geometry to one N(3), one Se(1), two equivalent Se(4), two equivalent Se(6), and two equivalent O(2) atoms. In the fourth Ce site, Ce(4) is bonded in a 3-coordinate geometry to one Se(2), two equivalent Se(3), two equivalent Se(5), one O(3), and two equivalent O(1) atoms. In the fifth Ce site, Ce(5) is bonded in a 3-coordinate geometry to one N(1), two equivalent N(2), one Se(1), and two equivalent Se(4) atoms. In the sixth Ce site, Ce(6) is bonded in a 3-coordinate geometry to one N(2), two equivalent N(1), one Se(2), and two equivalent Se(3) atoms. In the seventh Ce site, Ce(7) is bonded to one N(3), two equivalent Se(3), two equivalent Se(4), and one O(3) atom to form distorted edge-sharing CeSe4NO octahedra. In the eighth Ce site, Ce(8) is bonded to one N(1), one Se(5), two equivalent Se(2), and two equivalent Se(6) atoms to form distorted edge-sharing CeSe5N octahedra. In the ninth Ce site, Ce(9) is bonded to one N(2), one Se(6), two equivalent Se(1), and two equivalent Se(5) atoms to form distorted edge-sharing CeSe5N octahedra. There are three inequivalent N sites. In the first N site, N(1) is bonded to one Ce(5), one Ce(8), and two equivalent Ce(6) atoms to form NCe4 tetrahedra that share  a cornercorner with one Se(1)Ce6 octahedra,  a cornercorner with one Se(5)Ce5 square pyramid, corners with two equivalent Se(6)Ce5 square pyramids, corners with two equivalent N(1)Ce4 tetrahedra, edges with two equivalent Se(2)Ce6 octahedra, and edges with two equivalent N(2)Ce4 tetrahedra. The corner-sharing octahedral tilt angles are 44°. In the second N site, N(2) is bonded to one Ce(6), one Ce(9), and two equivalent Ce(5) atoms to form NCe4 tetrahedra that share  a cornercorner with one Se(2)Ce6 octahedra,  a cornercorner with one Se(6)Ce5 square pyramid, corners with two equivalent Se(5)Ce5 square pyramids, corners with two equivalent N(2)Ce4 tetrahedra, edges with two equivalent Se(1)Ce6 octahedra, and edges with two equivalent N(1)Ce4 tetrahedra. The corner-sharing octahedral tilt angles are 45°. In the third N site, N(3) is bonded to one Ce(3), one Ce(7), and two equivalent Ce(1) atoms to form NCe4 tetrahedra that share  a cornercorner with one Se(1)Ce6 octahedra, corners with two equivalent Se(2)Ce6 octahedra, corners with two equivalent Se(6)Ce5 square pyramids,  a cornercorner with one O(3)Ce4 tetrahedra, corners with two equivalent N(3)Ce4 tetrahedra, corners with two equivalent O(1)Ce4 tetrahedra,  an edgeedge with one Se(2)Ce6 octahedra, and edges with two equivalent O(2)Ce4 tetrahedra. The corner-sharing octahedral tilt angles range from 27-50°. There are six inequivalent Se sites. In the first Se site, Se(1) is bonded to one Ce(3), one Ce(5), two equivalent Ce(2), and two equivalent Ce(9) atoms to form SeCe6 octahedra that share corners with two equivalent Se(5)Ce5 square pyramids,  a cornercorner with one N(1)Ce4 tetrahedra,  a cornercorner with one N(3)Ce4 tetrahedra, corners with two equivalent O(1)Ce4 tetrahedra, corners with two equivalent O(3)Ce4 tetrahedra, edges with two equivalent Se(1)Ce6 octahedra,  an edgeedge with one Se(5)Ce5 square pyramid, edges with two equivalent Se(6)Ce5 square pyramids,  an edgeedge with one O(3)Ce4 tetrahedra, edges with two equivalent N(2)Ce4 tetrahedra, and edges with two equivalent O(2)Ce4 tetrahedra. In the second Se site, Se(2) is bonded to one Ce(4), one Ce(6), two equivalent Ce(1), and two equivalent Ce(8) atoms to form SeCe6 octahedra that share corners with two equivalent Se(6)Ce5 square pyramids,  a cornercorner with one N(2)Ce4 tetrahedra,  a cornercorner with one O(3)Ce4 tetrahedra, corners with two equivalent N(3)Ce4 tetrahedra, corners with two equivalent O(2)Ce4 tetrahedra, edges with two equivalent Se(2)Ce6 octahedra,  an edgeedge with one Se(6)Ce5 square pyramid, edges with two equivalent Se(5)Ce5 square pyramids,  an edgeedge with one N(3)Ce4 tetrahedra, edges with two equivalent N(1)Ce4 tetrahedra, and edges with two equivalent O(1)Ce4 tetrahedra. In the third Se site, Se(3) is bonded in a 7-coordinate geometry to one Ce(1), two equivalent Ce(4), two equivalent Ce(6), and two equivalent Ce(7) atoms. In the fourth Se site, Se(4) is bonded in a 7-coordinate geometry to one Ce(2), two equivalent Ce(3), two equivalent Ce(5), and two equivalent Ce(7) atoms. In the fifth Se site, Se(5) is bonded to one Ce(8), two equivalent Ce(4), and two equivalent Ce(9) atoms to form distorted SeCe5 square pyramids that share corners with two equivalent Se(1)Ce6 octahedra,  a cornercorner with one N(1)Ce4 tetrahedra, corners with two equivalent N(2)Ce4 tetrahedra, corners with two equivalent O(1)Ce4 tetrahedra, corners with two equivalent O(3)Ce4 tetrahedra,  an edgeedge with one Se(1)Ce6 octahedra, edges with two equivalent Se(2)Ce6 octahedra, edges with two equivalent Se(5)Ce5 square pyramids, edges with two equivalent Se(6)Ce5 square pyramids, and  an edgeedge with one O(1)Ce4 tetrahedra. The corner-sharing octahedral tilt angles are 4°. In the sixth Se site, Se(6) is bonded to one Ce(9), two equivalent Ce(3), and two equivalent Ce(8) atoms to form distorted SeCe5 square pyramids that share corners with two equivalent Se(2)Ce6 octahedra,  a cornercorner with one N(2)Ce4 tetrahedra, corners with two equivalent N(1)Ce4 tetrahedra, corners with two equivalent N(3)Ce4 tetrahedra, corners with two equivalent O(2)Ce4 tetrahedra,  an edgeedge with one Se(2)Ce6 octahedra, edges with two equivalent Se(1)Ce6 octahedra, edges with two equivalent Se(5)Ce5 square pyramids, edges with two equivalent Se(6)Ce5 square pyramids, and  an edgeedge with one O(2)Ce4 tetrahedra. The corner-sharing octahedral tilt angles are 4°. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Ce(1), one Ce(2), and two equivalent Ce(4) atoms to form OCe4 tetrahedra that share corners with two equivalent Se(1)Ce6 octahedra, corners with two equivalent Se(5)Ce5 square pyramids, corners with two equivalent N(3)Ce4 tetrahedra, corners with two equivalent O(1)Ce4 tetrahedra, edges with two equivalent Se(2)Ce6 octahedra,  an edgeedge with one Se(5)Ce5 square pyramid,  an edgeedge with one O(2)Ce4 tetrahedra, and edges with two equivalent O(3)Ce4 tetrahedra. The corner-sharing octahedral tilt angles are 48°. In the second O site, O(2) is bonded to one Ce(1), one Ce(2), and two equivalent Ce(3) atoms to form OCe4 tetrahedra that share corners with two equivalent Se(2)Ce6 octahedra, corners with two equivalent Se(6)Ce5 square pyramids, corners with two equivalent O(2)Ce4 tetrahedra, corners with two equivalent O(3)Ce4 tetrahedra, edges with two equivalent Se(1)Ce6 octahedra,  an edgeedge with one Se(6)Ce5 square pyramid,  an edgeedge with one O(1)Ce4 tetrahedra, and edges with two equivalent N(3)Ce4 tetrahedra. The corner-sharing octahedral tilt angles are 48°. In the third O site, O(3) is bonded to one Ce(4), one Ce(7), and two equivalent Ce(2) atoms to form OCe4 tetrahedra that share  a cornercorner with one Se(2)Ce6 octahedra, corners with two equivalent Se(1)Ce6 octahedra, corners with two equivalent Se(5)Ce5 square pyramids,  a cornercorner with one N(3)Ce4 tetrahedra, corners with two equivalent O(2)Ce4 tetrahedra, corners with two equivalent O(3)Ce4 tetrahedra,  an edgeedge with one Se(1)Ce6 octahedra, and edges with two equivalent O(1)Ce4 tetrahedra. The corner-sharing octahedral tilt angles range from 27-52°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ce3Se2NO
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.422
_cell_length_b   12.422
_cell_length_c   9.367
_cell_angle_alpha   84.608
_cell_angle_beta   84.608
_cell_angle_gamma   18.586
_symmetry_Int_Tables_number   1
_cell_volume   458.605
_cell_formula_units_Z   3
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  0.462  0.462  0.679  1.0
  Ce  Ce1  1  0.538  0.538  0.321  1.0
  Ce  Ce2  1  0.090  0.090  0.648  1.0
  Ce  Ce3  1  0.907  0.907  0.353  1.0
  Ce  Ce4  1  0.188  0.188  0.009  1.0
  Ce  Ce5  1  0.813  0.813  0.992  1.0
  Ce  Ce6  1  0.000  0.000  0.995  1.0
  Ce  Ce7  1  0.280  0.280  0.663  1.0
  Ce  Ce8  1  0.719  0.719  0.337  1.0
  Se  Se9  1  0.132  0.132  0.325  1.0
  Se  Se10  1  0.868  0.868  0.673  1.0
  Se  Se11  1  0.412  0.412  0.036  1.0
  Se  Se12  1  0.589  0.589  0.970  1.0
  Se  Se13  1  0.310  0.310  0.329  1.0
  Se  Se14  1  0.690  0.690  0.672  1.0
  N  N15  1  0.276  0.276  0.901  1.0
  N  N16  1  0.724  0.724  0.099  1.0
  N  N17  1  0.002  0.002  0.756  1.0
  O  O18  1  0.448  0.448  0.430  1.0
  O  O19  1  0.553  0.553  0.563  1.0
  O  O20  1  0.998  0.998  0.247  1.0
[/CIF]
.
The compound described by Ce3NSe2O crystallizes in the monoclinic Cm space group. There are nine inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 4-coordinate geometry to two equivalent N(3), one Se(3), two equivalent Se(2), one O(1), and one O(2) atom. In the second Ce site, Ce(2) is bonded in a 4-coordinate geometry to one Se(4), two equivalent Se(1), one O(1), one O(2), and two equivalent O(3) atoms. In the third Ce site, Ce(3) is bonded in a 3-coordinate geometry to one N(3), one Se(1), two equivalent Se(4), two equivalent Se(6), and two equivalent O(2) atoms. In the fourth Ce site, Ce(4) is bonded in a 3-coordinate geometry to one Se(2), two equivalent Se(3), two equivalent Se(5), one O(3), and two equivalent O(1) atoms. In the fifth Ce site, Ce(5) is bonded in a 3-coordinate geometry to one N(1), two equivalent N(2), one Se(1), and two equivalent Se(4) atoms. In the sixth Ce site, Ce(6) is bonded in a 3-coordinate geometry to one N(2), two equivalent N(1), one Se(2), and two equivalent Se(3) atoms. In the seventh Ce site, Ce(7) is bonded to one N(3), two equivalent Se(3), two equivalent Se(4), and one O(3) atom to form distorted edge-sharing CeSe4NO octahedra. In the eighth Ce site, Ce(8) is bonded to one N(1), one Se(5), two equivalent Se(2), and two equivalent Se(6) atoms to form distorted edge-sharing CeSe5N octahedra. In the ninth Ce site, Ce(9) is bonded to one N(2), one Se(6), two equivalent Se(1), and two equivalent Se(5) atoms to form distorted edge-sharing CeSe5N octahedra. There are three inequivalent N sites. In the first N site, N(1) is bonded to one Ce(5), one Ce(8), and two equivalent Ce(6) atoms to form NCe4 tetrahedra that share  a cornercorner with one Se(1)Ce6 octahedra,  a cornercorner with one Se(5)Ce5 square pyramid, corners with two equivalent Se(6)Ce5 square pyramids, corners with two equivalent N(1)Ce4 tetrahedra, edges with two equivalent Se(2)Ce6 octahedra, and edges with two equivalent N(2)Ce4 tetrahedra. The corner-sharing octahedral tilt angles are 44°. In the second N site, N(2) is bonded to one Ce(6), one Ce(9), and two equivalent Ce(5) atoms to form NCe4 tetrahedra that share  a cornercorner with one Se(2)Ce6 octahedra,  a cornercorner with one Se(6)Ce5 square pyramid, corners with two equivalent Se(5)Ce5 square pyramids, corners with two equivalent N(2)Ce4 tetrahedra, edges with two equivalent Se(1)Ce6 octahedra, and edges with two equivalent N(1)Ce4 tetrahedra. The corner-sharing octahedral tilt angles are 45°. In the third N site, N(3) is bonded to one Ce(3), one Ce(7), and two equivalent Ce(1) atoms to form NCe4 tetrahedra that share  a cornercorner with one Se(1)Ce6 octahedra, corners with two equivalent Se(2)Ce6 octahedra, corners with two equivalent Se(6)Ce5 square pyramids,  a cornercorner with one O(3)Ce4 tetrahedra, corners with two equivalent N(3)Ce4 tetrahedra, corners with two equivalent O(1)Ce4 tetrahedra,  an edgeedge with one Se(2)Ce6 octahedra, and edges with two equivalent O(2)Ce4 tetrahedra. The corner-sharing octahedral tilt angles range from 27-50°. There are six inequivalent Se sites. In the first Se site, Se(1) is bonded to one Ce(3), one Ce(5), two equivalent Ce(2), and two equivalent Ce(9) atoms to form SeCe6 octahedra that share corners with two equivalent Se(5)Ce5 square pyramids,  a cornercorner with one N(1)Ce4 tetrahedra,  a cornercorner with one N(3)Ce4 tetrahedra, corners with two equivalent O(1)Ce4 tetrahedra, corners with two equivalent O(3)Ce4 tetrahedra, edges with two equivalent Se(1)Ce6 octahedra,  an edgeedge with one Se(5)Ce5 square pyramid, edges with two equivalent Se(6)Ce5 square pyramids,  an edgeedge with one O(3)Ce4 tetrahedra, edges with two equivalent N(2)Ce4 tetrahedra, and edges with two equivalent O(2)Ce4 tetrahedra. In the second Se site, Se(2) is bonded to one Ce(4), one Ce(6), two equivalent Ce(1), and two equivalent Ce(8) atoms to form SeCe6 octahedra that share corners with two equivalent Se(6)Ce5 square pyramids,  a cornercorner with one N(2)Ce4 tetrahedra,  a cornercorner with one O(3)Ce4 tetrahedra, corners with two equivalent N(3)Ce4 tetrahedra, corners with two equivalent O(2)Ce4 tetrahedra, edges with two equivalent Se(2)Ce6 octahedra,  an edgeedge with one Se(6)Ce5 square pyramid, edges with two equivalent Se(5)Ce5 square pyramids,  an edgeedge with one N(3)Ce4 tetrahedra, edges with two equivalent N(1)Ce4 tetrahedra, and edges with two equivalent O(1)Ce4 tetrahedra. In the third Se site, Se(3) is bonded in a 7-coordinate geometry to one Ce(1), two equivalent Ce(4), two equivalent Ce(6), and two equivalent Ce(7) atoms. In the fourth Se site, Se(4) is bonded in a 7-coordinate geometry to one Ce(2), two equivalent Ce(3), two equivalent Ce(5), and two equivalent Ce(7) atoms. In the fifth Se site, Se(5) is bonded to one Ce(8), two equivalent Ce(4), and two equivalent Ce(9) atoms to form distorted SeCe5 square pyramids that share corners with two equivalent Se(1)Ce6 octahedra,  a cornercorner with one N(1)Ce4 tetrahedra, corners with two equivalent N(2)Ce4 tetrahedra, corners with two equivalent O(1)Ce4 tetrahedra, corners with two equivalent O(3)Ce4 tetrahedra,  an edgeedge with one Se(1)Ce6 octahedra, edges with two equivalent Se(2)Ce6 octahedra, edges with two equivalent Se(5)Ce5 square pyramids, edges with two equivalent Se(6)Ce5 square pyramids, and  an edgeedge with one O(1)Ce4 tetrahedra. The corner-sharing octahedral tilt angles are 4°. In the sixth Se site, Se(6) is bonded to one Ce(9), two equivalent Ce(3), and two equivalent Ce(8) atoms to form distorted SeCe5 square pyramids that share corners with two equivalent Se(2)Ce6 octahedra,  a cornercorner with one N(2)Ce4 tetrahedra, corners with two equivalent N(1)Ce4 tetrahedra, corners with two equivalent N(3)Ce4 tetrahedra, corners with two equivalent O(2)Ce4 tetrahedra,  an edgeedge with one Se(2)Ce6 octahedra, edges with two equivalent Se(1)Ce6 octahedra, edges with two equivalent Se(5)Ce5 square pyramids, edges with two equivalent Se(6)Ce5 square pyramids, and  an edgeedge with one O(2)Ce4 tetrahedra. The corner-sharing octahedral tilt angles are 4°. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Ce(1), one Ce(2), and two equivalent Ce(4) atoms to form OCe4 tetrahedra that share corners with two equivalent Se(1)Ce6 octahedra, corners with two equivalent Se(5)Ce5 square pyramids, corners with two equivalent N(3)Ce4 tetrahedra, corners with two equivalent O(1)Ce4 tetrahedra, edges with two equivalent Se(2)Ce6 octahedra,  an edgeedge with one Se(5)Ce5 square pyramid,  an edgeedge with one O(2)Ce4 tetrahedra, and edges with two equivalent O(3)Ce4 tetrahedra. The corner-sharing octahedral tilt angles are 48°. In the second O site, O(2) is bonded to one Ce(1), one Ce(2), and two equivalent Ce(3) atoms to form OCe4 tetrahedra that share corners with two equivalent Se(2)Ce6 octahedra, corners with two equivalent Se(6)Ce5 square pyramids, corners with two equivalent O(2)Ce4 tetrahedra, corners with two equivalent O(3)Ce4 tetrahedra, edges with two equivalent Se(1)Ce6 octahedra,  an edgeedge with one Se(6)Ce5 square pyramid,  an edgeedge with one O(1)Ce4 tetrahedra, and edges with two equivalent N(3)Ce4 tetrahedra. The corner-sharing octahedral tilt angles are 48°. In the third O site, O(3) is bonded to one Ce(4), one Ce(7), and two equivalent Ce(2) atoms to form OCe4 tetrahedra that share  a cornercorner with one Se(2)Ce6 octahedra, corners with two equivalent Se(1)Ce6 octahedra, corners with two equivalent Se(5)Ce5 square pyramids,  a cornercorner with one N(3)Ce4 tetrahedra, corners with two equivalent O(2)Ce4 tetrahedra, corners with two equivalent O(3)Ce4 tetrahedra,  an edgeedge with one Se(1)Ce6 octahedra, and edges with two equivalent O(1)Ce4 tetrahedra. The corner-sharing octahedral tilt angles range from 27-52°. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ce3Se2NO
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.422
_cell_length_b   12.422
_cell_length_c   9.367
_cell_angle_alpha   84.608
_cell_angle_beta   84.608
_cell_angle_gamma   18.586
_symmetry_Int_Tables_number   1
_cell_volume   458.605
_cell_formula_units_Z   3
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  0.462  0.462  0.679  1.0
  Ce  Ce1  1  0.538  0.538  0.321  1.0
  Ce  Ce2  1  0.090  0.090  0.648  1.0
  Ce  Ce3  1  0.907  0.907  0.353  1.0
  Ce  Ce4  1  0.188  0.188  0.009  1.0
  Ce  Ce5  1  0.813  0.813  0.992  1.0
  Ce  Ce6  1  0.000  0.000  0.995  1.0
  Ce  Ce7  1  0.280  0.280  0.663  1.0
  Ce  Ce8  1  0.719  0.719  0.337  1.0
  Se  Se9  1  0.132  0.132  0.325  1.0
  Se  Se10  1  0.868  0.868  0.673  1.0
  Se  Se11  1  0.412  0.412  0.036  1.0
  Se  Se12  1  0.589  0.589  0.970  1.0
  Se  Se13  1  0.310  0.310  0.329  1.0
  Se  Se14  1  0.690  0.690  0.672  1.0
  N  N15  1  0.276  0.276  0.901  1.0
  N  N16  1  0.724  0.724  0.099  1.0
  N  N17  1  0.002  0.002  0.756  1.0
  O  O18  1  0.448  0.448  0.430  1.0
  O  O19  1  0.553  0.553  0.563  1.0
  O  O20  1  0.998  0.998  0.247  1.0
[/CIF]
.