The crystal structure described by RbMg14CrO16 is Molybdenum Carbide MAX Phase-derived structured and crystallizes in the tetragonal P4/mmm space group. Rb(1) is bonded to two equivalent O(4) and four equivalent O(1) atoms to form RbO6 octahedra that share corners with two equivalent Rb(1)O6 octahedra; corners with four equivalent Mg(1)O6 octahedra; edges with four equivalent Mg(4)O6 octahedra; and edges with eight Mg(2,2)O6 octahedra. The corner-sharing octahedra are not tilted. There are five inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms to form MgO6 octahedra that share corners with two equivalent Rb(1)O6 octahedra; corners with two equivalent Mg(1)O6 octahedra; corners with two equivalent Cr(1)O6 octahedra; edges with four Mg(2,2)O6 octahedra; edges with four equivalent Mg(3)O6 octahedra; and edges with four equivalent Mg(4)O6 octahedra. The corner-sharing octahedra are not tilted. In the second Mg site, Mg(2) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(3)O6 octahedra; corners with four Mg(2,2)O6 octahedra; edges with two equivalent Rb(1)O6 octahedra; edges with two equivalent Mg(1)O6 octahedra; edges with two Mg(2,2)O6 octahedra; edges with two equivalent Mg(3)O6 octahedra; and edges with four equivalent Mg(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the third Mg site, Mg(2) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(3)O6 octahedra; corners with four Mg(2,2)O6 octahedra; edges with two equivalent Rb(1)O6 octahedra; edges with two equivalent Mg(1)O6 octahedra; edges with two Mg(2,2)O6 octahedra; edges with two equivalent Mg(3)O6 octahedra; and edges with four equivalent Mg(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the fourth Mg site, Mg(3) is bonded to one O(5), one O(6), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra; corners with four equivalent Mg(3)O6 octahedra; edges with two equivalent Mg(1)O6 octahedra; edges with two Mg(2,2)O6 octahedra; edges with two equivalent Mg(3)O6 octahedra; edges with two equivalent Cr(1)O6 octahedra; and edges with four equivalent Mg(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-6°. In the fifth Mg site, Mg(4) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with six equivalent Mg(4)O6 octahedra,  an edgeedge with one Rb(1)O6 octahedra,  an edgeedge with one Cr(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(2)O6 octahedra, and edges with four equivalent Mg(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-14°. Cr(1) is bonded to two equivalent O(6) and four equivalent O(2) atoms to form CrO6 octahedra that share corners with two equivalent Cr(1)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(4)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Rb(1), one Mg(1), two equivalent Mg(2), and two equivalent Mg(4) atoms to form ORbMg5 octahedra that share corners with two equivalent O(2)Mg5Cr octahedra, corners with four equivalent O(1)RbMg5 octahedra, edges with two equivalent O(2)Mg5Cr octahedra, edges with two equivalent O(5)Mg6 octahedra, edges with two equivalent O(4)Rb2Mg4 octahedra, edges with two equivalent O(1)RbMg5 octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the second O site, O(2) is bonded to one Mg(1), two equivalent Mg(3), two equivalent Mg(4), and one Cr(1) atom to form OMg5Cr octahedra that share corners with two equivalent O(1)RbMg5 octahedra, corners with four equivalent O(2)Mg5Cr octahedra, edges with two equivalent O(6)Mg4Cr2 octahedra, edges with two equivalent O(2)Mg5Cr octahedra, edges with two equivalent O(5)Mg6 octahedra, edges with two equivalent O(1)RbMg5 octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-9°. In the third O site, O(3) is bonded to two equivalent Mg(2), two equivalent Mg(3), and two equivalent Mg(4) atoms to form OMg6 octahedra that share corners with six equivalent O(3)Mg6 octahedra,  an edgeedge with one O(6)Mg4Cr2 octahedra,  an edgeedge with one O(4)Rb2Mg4 octahedra, edges with two equivalent O(5)Mg6 octahedra, edges with four equivalent O(2)Mg5Cr octahedra, and edges with four equivalent O(1)RbMg5 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the fourth O site, O(4) is bonded to two equivalent Rb(1) and four Mg(2,2) atoms to form ORb2Mg4 octahedra that share corners with two equivalent O(4)Rb2Mg4 octahedra, corners with four equivalent O(5)Mg6 octahedra, edges with four equivalent O(3)Mg6 octahedra, and edges with eight equivalent O(1)RbMg5 octahedra. The corner-sharing octahedra are not tilted. In the fifth O site, O(5) is bonded to two equivalent Mg(1); two Mg(2,2); and two equivalent Mg(3) atoms to form OMg6 octahedra that share corners with two equivalent O(6)Mg4Cr2 octahedra, corners with two equivalent O(5)Mg6 octahedra, corners with two equivalent O(4)Rb2Mg4 octahedra, edges with four equivalent O(2)Mg5Cr octahedra, edges with four equivalent O(3)Mg6 octahedra, and edges with four equivalent O(1)RbMg5 octahedra. The corner-sharing octahedra are not tilted. In the sixth O site, O(6) is bonded to four equivalent Mg(3) and two equivalent Cr(1) atoms to form OMg4Cr2 octahedra that share corners with two equivalent O(6)Mg4Cr2 octahedra, corners with four equivalent O(5)Mg6 octahedra, edges with four equivalent O(3)Mg6 octahedra, and edges with eight equivalent O(2)Mg5Cr octahedra. The corner-sharing octahedra are not tilted. is represented by the CIF card [CIF]
data_RbMg14CrO16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.713
_cell_length_b   8.713
_cell_length_c   4.395
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   333.662
_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  0.000  0.000  0.000  1.0
  Mg  Mg1  1  0.000  0.500  0.000  1.0
  Mg  Mg2  1  0.500  0.000  0.000  1.0
  Mg  Mg3  1  0.000  0.258  0.500  1.0
  Mg  Mg4  1  0.000  0.742  0.500  1.0
  Mg  Mg5  1  0.500  0.249  0.500  1.0
  Mg  Mg6  1  0.500  0.751  0.500  1.0
  Mg  Mg7  1  0.258  0.000  0.500  1.0
  Mg  Mg8  1  0.249  0.500  0.500  1.0
  Mg  Mg9  1  0.742  0.000  0.500  1.0
  Mg  Mg10  1  0.751  0.500  0.500  1.0
  Mg  Mg11  1  0.251  0.251  0.000  1.0
  Mg  Mg12  1  0.251  0.749  0.000  1.0
  Mg  Mg13  1  0.749  0.251  0.000  1.0
  Mg  Mg14  1  0.749  0.749  0.000  1.0
  Cr  Cr15  1  0.500  0.500  0.000  1.0
  O  O16  1  0.281  0.000  0.000  1.0
  O  O17  1  0.262  0.500  0.000  1.0
  O  O18  1  0.719  0.000  0.000  1.0
  O  O19  1  0.738  0.500  0.000  1.0
  O  O20  1  0.251  0.251  0.500  1.0
  O  O21  1  0.251  0.749  0.500  1.0
  O  O22  1  0.749  0.251  0.500  1.0
  O  O23  1  0.749  0.749  0.500  1.0
  O  O24  1  0.000  0.000  0.500  1.0
  O  O25  1  0.000  0.500  0.500  1.0
  O  O26  1  0.500  0.000  0.500  1.0
  O  O27  1  0.500  0.500  0.500  1.0
  O  O28  1  0.000  0.281  0.000  1.0
  O  O29  1  0.000  0.719  0.000  1.0
  O  O30  1  0.500  0.262  0.000  1.0
  O  O31  1  0.500  0.738  0.000  1.0
[/CIF]
.
The crystal structure described by RbMg14CrO16 is Molybdenum Carbide MAX Phase-derived structured and crystallizes in the tetragonal P4/mmm space group. Rb(1) is bonded to two equivalent O(4) and four equivalent O(1) atoms to form RbO6 octahedra that share corners with two equivalent Rb(1)O6 octahedra; corners with four equivalent Mg(1)O6 octahedra; edges with four equivalent Mg(4)O6 octahedra; and edges with eight Mg(2,2)O6 octahedra. The corner-sharing octahedra are not tilted. There are five inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms to form MgO6 octahedra that share corners with two equivalent Rb(1)O6 octahedra; corners with two equivalent Mg(1)O6 octahedra; corners with two equivalent Cr(1)O6 octahedra; edges with four Mg(2,2)O6 octahedra; edges with four equivalent Mg(3)O6 octahedra; and edges with four equivalent Mg(4)O6 octahedra. The corner-sharing octahedra are not tilted. In the second Mg site, Mg(2) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(3)O6 octahedra; corners with four Mg(2,2)O6 octahedra; edges with two equivalent Rb(1)O6 octahedra; edges with two equivalent Mg(1)O6 octahedra; edges with two Mg(2,2)O6 octahedra; edges with two equivalent Mg(3)O6 octahedra; and edges with four equivalent Mg(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the third Mg site, Mg(2) is bonded to one O(4), one O(5), two equivalent O(1), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(3)O6 octahedra; corners with four Mg(2,2)O6 octahedra; edges with two equivalent Rb(1)O6 octahedra; edges with two equivalent Mg(1)O6 octahedra; edges with two Mg(2,2)O6 octahedra; edges with two equivalent Mg(3)O6 octahedra; and edges with four equivalent Mg(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the fourth Mg site, Mg(3) is bonded to one O(5), one O(6), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra; corners with four equivalent Mg(3)O6 octahedra; edges with two equivalent Mg(1)O6 octahedra; edges with two Mg(2,2)O6 octahedra; edges with two equivalent Mg(3)O6 octahedra; edges with two equivalent Cr(1)O6 octahedra; and edges with four equivalent Mg(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-6°. In the fifth Mg site, Mg(4) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with six equivalent Mg(4)O6 octahedra,  an edgeedge with one Rb(1)O6 octahedra,  an edgeedge with one Cr(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(2)O6 octahedra, and edges with four equivalent Mg(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-14°. Cr(1) is bonded to two equivalent O(6) and four equivalent O(2) atoms to form CrO6 octahedra that share corners with two equivalent Cr(1)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(4)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. There are six inequivalent O sites. In the first O site, O(1) is bonded to one Rb(1), one Mg(1), two equivalent Mg(2), and two equivalent Mg(4) atoms to form ORbMg5 octahedra that share corners with two equivalent O(2)Mg5Cr octahedra, corners with four equivalent O(1)RbMg5 octahedra, edges with two equivalent O(2)Mg5Cr octahedra, edges with two equivalent O(5)Mg6 octahedra, edges with two equivalent O(4)Rb2Mg4 octahedra, edges with two equivalent O(1)RbMg5 octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the second O site, O(2) is bonded to one Mg(1), two equivalent Mg(3), two equivalent Mg(4), and one Cr(1) atom to form OMg5Cr octahedra that share corners with two equivalent O(1)RbMg5 octahedra, corners with four equivalent O(2)Mg5Cr octahedra, edges with two equivalent O(6)Mg4Cr2 octahedra, edges with two equivalent O(2)Mg5Cr octahedra, edges with two equivalent O(5)Mg6 octahedra, edges with two equivalent O(1)RbMg5 octahedra, and edges with four equivalent O(3)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-9°. In the third O site, O(3) is bonded to two equivalent Mg(2), two equivalent Mg(3), and two equivalent Mg(4) atoms to form OMg6 octahedra that share corners with six equivalent O(3)Mg6 octahedra,  an edgeedge with one O(6)Mg4Cr2 octahedra,  an edgeedge with one O(4)Rb2Mg4 octahedra, edges with two equivalent O(5)Mg6 octahedra, edges with four equivalent O(2)Mg5Cr octahedra, and edges with four equivalent O(1)RbMg5 octahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the fourth O site, O(4) is bonded to two equivalent Rb(1) and four Mg(2,2) atoms to form ORb2Mg4 octahedra that share corners with two equivalent O(4)Rb2Mg4 octahedra, corners with four equivalent O(5)Mg6 octahedra, edges with four equivalent O(3)Mg6 octahedra, and edges with eight equivalent O(1)RbMg5 octahedra. The corner-sharing octahedra are not tilted. In the fifth O site, O(5) is bonded to two equivalent Mg(1); two Mg(2,2); and two equivalent Mg(3) atoms to form OMg6 octahedra that share corners with two equivalent O(6)Mg4Cr2 octahedra, corners with two equivalent O(5)Mg6 octahedra, corners with two equivalent O(4)Rb2Mg4 octahedra, edges with four equivalent O(2)Mg5Cr octahedra, edges with four equivalent O(3)Mg6 octahedra, and edges with four equivalent O(1)RbMg5 octahedra. The corner-sharing octahedra are not tilted. In the sixth O site, O(6) is bonded to four equivalent Mg(3) and two equivalent Cr(1) atoms to form OMg4Cr2 octahedra that share corners with two equivalent O(6)Mg4Cr2 octahedra, corners with four equivalent O(5)Mg6 octahedra, edges with four equivalent O(3)Mg6 octahedra, and edges with eight equivalent O(2)Mg5Cr octahedra. The corner-sharing octahedra are not tilted. is represented by the CIF card [CIF]
data_RbMg14CrO16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.713
_cell_length_b   8.713
_cell_length_c   4.395
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   333.662
_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  0.000  0.000  0.000  1.0
  Mg  Mg1  1  0.000  0.500  0.000  1.0
  Mg  Mg2  1  0.500  0.000  0.000  1.0
  Mg  Mg3  1  0.000  0.258  0.500  1.0
  Mg  Mg4  1  0.000  0.742  0.500  1.0
  Mg  Mg5  1  0.500  0.249  0.500  1.0
  Mg  Mg6  1  0.500  0.751  0.500  1.0
  Mg  Mg7  1  0.258  0.000  0.500  1.0
  Mg  Mg8  1  0.249  0.500  0.500  1.0
  Mg  Mg9  1  0.742  0.000  0.500  1.0
  Mg  Mg10  1  0.751  0.500  0.500  1.0
  Mg  Mg11  1  0.251  0.251  0.000  1.0
  Mg  Mg12  1  0.251  0.749  0.000  1.0
  Mg  Mg13  1  0.749  0.251  0.000  1.0
  Mg  Mg14  1  0.749  0.749  0.000  1.0
  Cr  Cr15  1  0.500  0.500  0.000  1.0
  O  O16  1  0.281  0.000  0.000  1.0
  O  O17  1  0.262  0.500  0.000  1.0
  O  O18  1  0.719  0.000  0.000  1.0
  O  O19  1  0.738  0.500  0.000  1.0
  O  O20  1  0.251  0.251  0.500  1.0
  O  O21  1  0.251  0.749  0.500  1.0
  O  O22  1  0.749  0.251  0.500  1.0
  O  O23  1  0.749  0.749  0.500  1.0
  O  O24  1  0.000  0.000  0.500  1.0
  O  O25  1  0.000  0.500  0.500  1.0
  O  O26  1  0.500  0.000  0.500  1.0
  O  O27  1  0.500  0.500  0.500  1.0
  O  O28  1  0.000  0.281  0.000  1.0
  O  O29  1  0.000  0.719  0.000  1.0
  O  O30  1  0.500  0.262  0.000  1.0
  O  O31  1  0.500  0.738  0.000  1.0
[/CIF]
.