The material structure described by RbMg6CeO8 is Caswellsilverite-derived structured and crystallizes in the tetragonal P4/mmm space group. Rb(1) is bonded to two equivalent O(1) and four equivalent O(4) atoms to form RbO6 octahedra that share corners with two equivalent Ce(1)O6 octahedra, corners with four equivalent Rb(1)O6 octahedra, edges with four equivalent Mg(2)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, edges with four equivalent Ce(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. In the second Mg site, Mg(2) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Mg(2)O6 octahedra, edges with four equivalent Rb(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. In the third Mg site, Mg(3) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form MgO6 octahedra that share corners with six equivalent Mg(3)O6 octahedra, edges with two equivalent Rb(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, edges with two equivalent Ce(1)O6 octahedra, and edges with four equivalent Mg(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-16°. Ce(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form CeO6 octahedra that share corners with two equivalent Rb(1)O6 octahedra, corners with four equivalent Ce(1)O6 octahedra, edges with four equivalent Mg(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Rb(1), four equivalent Mg(3), and one Ce(1) atom to form ORbCeMg4 octahedra that share corners with six equivalent O(1)RbCeMg4 octahedra, edges with four equivalent O(3)Ce2Mg4 octahedra, edges with four equivalent O(2)Mg6 octahedra, and edges with four equivalent O(4)Rb2Mg4 octahedra. The corner-sharing octahedral tilt angles range from 0-16°. In the second O site, O(2) is bonded to one Mg(1), one Mg(2), and four equivalent Mg(3) atoms to form OMg6 octahedra that share corners with six equivalent O(2)Mg6 octahedra, edges with four equivalent O(3)Ce2Mg4 octahedra, edges with four equivalent O(4)Rb2Mg4 octahedra, and edges with four equivalent O(1)RbCeMg4 octahedra. The corner-sharing octahedral tilt angles range from 0-9°. In the third O site, O(3) is bonded to two equivalent Mg(1), two equivalent Mg(3), and two equivalent Ce(1) atoms to form OCe2Mg4 octahedra that share corners with two equivalent O(4)Rb2Mg4 octahedra, corners with four equivalent O(3)Ce2Mg4 octahedra, edges with four equivalent O(3)Ce2Mg4 octahedra, edges with four equivalent O(2)Mg6 octahedra, and edges with four equivalent O(1)RbCeMg4 octahedra. The corner-sharing octahedra are not tilted. In the fourth O site, O(4) is bonded to two equivalent Rb(1), two equivalent Mg(2), and two equivalent Mg(3) atoms to form ORb2Mg4 octahedra that share corners with two equivalent O(3)Ce2Mg4 octahedra, corners with four equivalent O(4)Rb2Mg4 octahedra, edges with four equivalent O(2)Mg6 octahedra, edges with four equivalent O(4)Rb2Mg4 octahedra, and edges with four equivalent O(1)RbCeMg4 octahedra. The corner-sharing octahedra are not tilted. is represented by the CIF file [CIF]
data_RbCeMg6O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.185
_cell_length_b   4.725
_cell_length_c   4.725
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   205.088
_cell_formula_units_Z   1
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
  Rb  Rb0  1  0.500  0.000  0.000  1.0
  Ce  Ce1  1  0.000  0.000  0.000  1.0
  Mg  Mg2  1  0.000  0.500  0.500  1.0
  Mg  Mg3  1  0.500  0.500  0.500  1.0
  Mg  Mg4  1  0.271  0.000  0.500  1.0
  Mg  Mg5  1  0.729  0.000  0.500  1.0
  Mg  Mg6  1  0.271  0.500  0.000  1.0
  Mg  Mg7  1  0.729  0.500  0.000  1.0
  O  O8  1  0.234  0.000  0.000  1.0
  O  O9  1  0.766  0.000  0.000  1.0
  O  O10  1  0.250  0.500  0.500  1.0
  O  O11  1  0.750  0.500  0.500  1.0
  O  O12  1  0.000  0.000  0.500  1.0
  O  O13  1  0.500  0.000  0.500  1.0
  O  O14  1  0.000  0.500  0.000  1.0
  O  O15  1  0.500  0.500  0.000  1.0
[/CIF]
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The material structure described by RbMg6CeO8 is Caswellsilverite-derived structured and crystallizes in the tetragonal P4/mmm space group. Rb(1) is bonded to two equivalent O(1) and four equivalent O(4) atoms to form RbO6 octahedra that share corners with two equivalent Ce(1)O6 octahedra, corners with four equivalent Rb(1)O6 octahedra, edges with four equivalent Mg(2)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, edges with four equivalent Ce(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. In the second Mg site, Mg(2) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Mg(2)O6 octahedra, edges with four equivalent Rb(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. In the third Mg site, Mg(3) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form MgO6 octahedra that share corners with six equivalent Mg(3)O6 octahedra, edges with two equivalent Rb(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, edges with two equivalent Ce(1)O6 octahedra, and edges with four equivalent Mg(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-16°. Ce(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form CeO6 octahedra that share corners with two equivalent Rb(1)O6 octahedra, corners with four equivalent Ce(1)O6 octahedra, edges with four equivalent Mg(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Rb(1), four equivalent Mg(3), and one Ce(1) atom to form ORbCeMg4 octahedra that share corners with six equivalent O(1)RbCeMg4 octahedra, edges with four equivalent O(3)Ce2Mg4 octahedra, edges with four equivalent O(2)Mg6 octahedra, and edges with four equivalent O(4)Rb2Mg4 octahedra. The corner-sharing octahedral tilt angles range from 0-16°. In the second O site, O(2) is bonded to one Mg(1), one Mg(2), and four equivalent Mg(3) atoms to form OMg6 octahedra that share corners with six equivalent O(2)Mg6 octahedra, edges with four equivalent O(3)Ce2Mg4 octahedra, edges with four equivalent O(4)Rb2Mg4 octahedra, and edges with four equivalent O(1)RbCeMg4 octahedra. The corner-sharing octahedral tilt angles range from 0-9°. In the third O site, O(3) is bonded to two equivalent Mg(1), two equivalent Mg(3), and two equivalent Ce(1) atoms to form OCe2Mg4 octahedra that share corners with two equivalent O(4)Rb2Mg4 octahedra, corners with four equivalent O(3)Ce2Mg4 octahedra, edges with four equivalent O(3)Ce2Mg4 octahedra, edges with four equivalent O(2)Mg6 octahedra, and edges with four equivalent O(1)RbCeMg4 octahedra. The corner-sharing octahedra are not tilted. In the fourth O site, O(4) is bonded to two equivalent Rb(1), two equivalent Mg(2), and two equivalent Mg(3) atoms to form ORb2Mg4 octahedra that share corners with two equivalent O(3)Ce2Mg4 octahedra, corners with four equivalent O(4)Rb2Mg4 octahedra, edges with four equivalent O(2)Mg6 octahedra, edges with four equivalent O(4)Rb2Mg4 octahedra, and edges with four equivalent O(1)RbCeMg4 octahedra. The corner-sharing octahedra are not tilted. is represented by the CIF file [CIF]
data_RbCeMg6O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.185
_cell_length_b   4.725
_cell_length_c   4.725
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   205.088
_cell_formula_units_Z   1
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
  Rb  Rb0  1  0.500  0.000  0.000  1.0
  Ce  Ce1  1  0.000  0.000  0.000  1.0
  Mg  Mg2  1  0.000  0.500  0.500  1.0
  Mg  Mg3  1  0.500  0.500  0.500  1.0
  Mg  Mg4  1  0.271  0.000  0.500  1.0
  Mg  Mg5  1  0.729  0.000  0.500  1.0
  Mg  Mg6  1  0.271  0.500  0.000  1.0
  Mg  Mg7  1  0.729  0.500  0.000  1.0
  O  O8  1  0.234  0.000  0.000  1.0
  O  O9  1  0.766  0.000  0.000  1.0
  O  O10  1  0.250  0.500  0.500  1.0
  O  O11  1  0.750  0.500  0.500  1.0
  O  O12  1  0.000  0.000  0.500  1.0
  O  O13  1  0.500  0.000  0.500  1.0
  O  O14  1  0.000  0.500  0.000  1.0
  O  O15  1  0.500  0.500  0.000  1.0
[/CIF]
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