The structure described by MgCeSe3 is Ilmenite structured and crystallizes in the trigonal R-3 space group. Mg(1) is bonded to six equivalent Se(1) atoms to form MgSe6 octahedra that share corners with nine equivalent Ce(1)Se6 octahedra, edges with three equivalent Mg(1)Se6 octahedra, and  a faceface with one Ce(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 47-58°. Ce(1) is bonded to six equivalent Se(1) atoms to form CeSe6 octahedra that share corners with nine equivalent Mg(1)Se6 octahedra, edges with three equivalent Ce(1)Se6 octahedra, and  a faceface with one Mg(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 47-58°. Se(1) is bonded to two equivalent Mg(1) and two equivalent Ce(1) atoms to form a mixture of distorted corner and edge-sharing SeCe2Mg2 trigonal pyramids. is represented by the CIF card [CIF]
data_CeMgSe3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.130
_cell_length_b   7.130
_cell_length_c   7.533
_cell_angle_alpha   61.755
_cell_angle_beta   61.755
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   277.796
_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  0.344  0.344  0.967  1.0
  Ce  Ce1  1  0.656  0.656  0.033  1.0
  Mg  Mg2  1  0.153  0.153  0.540  1.0
  Mg  Mg3  1  0.847  0.847  0.460  1.0
  Se  Se4  1  0.243  0.939  0.259  1.0
  Se  Se5  1  0.757  0.061  0.741  1.0
  Se  Se6  1  0.939  0.559  0.259  1.0
  Se  Se7  1  0.061  0.441  0.741  1.0
  Se  Se8  1  0.559  0.243  0.259  1.0
  Se  Se9  1  0.441  0.757  0.741  1.0
[/CIF]
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The structure described by MgCeSe3 is Ilmenite structured and crystallizes in the trigonal R-3 space group. Mg(1) is bonded to six equivalent Se(1) atoms to form MgSe6 octahedra that share corners with nine equivalent Ce(1)Se6 octahedra, edges with three equivalent Mg(1)Se6 octahedra, and  a faceface with one Ce(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 47-58°. Ce(1) is bonded to six equivalent Se(1) atoms to form CeSe6 octahedra that share corners with nine equivalent Mg(1)Se6 octahedra, edges with three equivalent Ce(1)Se6 octahedra, and  a faceface with one Mg(1)Se6 octahedra. The corner-sharing octahedral tilt angles range from 47-58°. Se(1) is bonded to two equivalent Mg(1) and two equivalent Ce(1) atoms to form a mixture of distorted corner and edge-sharing SeCe2Mg2 trigonal pyramids. is represented by the CIF card [CIF]
data_CeMgSe3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.130
_cell_length_b   7.130
_cell_length_c   7.533
_cell_angle_alpha   61.755
_cell_angle_beta   61.755
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   277.796
_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  0.344  0.344  0.967  1.0
  Ce  Ce1  1  0.656  0.656  0.033  1.0
  Mg  Mg2  1  0.153  0.153  0.540  1.0
  Mg  Mg3  1  0.847  0.847  0.460  1.0
  Se  Se4  1  0.243  0.939  0.259  1.0
  Se  Se5  1  0.757  0.061  0.741  1.0
  Se  Se6  1  0.939  0.559  0.259  1.0
  Se  Se7  1  0.061  0.441  0.741  1.0
  Se  Se8  1  0.559  0.243  0.259  1.0
  Se  Se9  1  0.441  0.757  0.741  1.0
[/CIF]
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