The structure described by RbNaMg6O7 crystallizes in the tetragonal P4mm space group. Rb(1) is bonded in a 5-coordinate geometry to one O(3) and four equivalent O(4) atoms. Na(1) is bonded in a square co-planar geometry to four equivalent O(4) atoms. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(1) and four equivalent O(5) atoms to form MgO5 square pyramids that share corners with four equivalent Mg(1)O5 square pyramids, edges with four equivalent Mg(2)O6 octahedra, and edges with four equivalent Mg(4)O5 square pyramids. In the second Mg site, Mg(2) is bonded to one O(2), one O(3), and four equivalent O(5) atoms to form MgO6 octahedra that share corners with four equivalent Mg(2)O6 octahedra, edges with four equivalent Mg(1)O5 square pyramids, and edges with four equivalent Mg(4)O5 square pyramids. The corner-sharing octahedral tilt angles are 5°. In the third Mg site, Mg(3) is bonded in a 4-coordinate geometry to one O(4), one O(5), and two equivalent O(2) atoms. In the fourth Mg site, Mg(4) is bonded to one O(5), two equivalent O(1), and two equivalent O(3) atoms to form MgO5 square pyramids that share corners with four equivalent Mg(4)O5 square pyramids, edges with two equivalent Mg(2)O6 octahedra, edges with two equivalent Mg(1)O5 square pyramids, and edges with four equivalent Mg(4)O5 square pyramids. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1) and four equivalent Mg(4) atoms to form OMg5 square pyramids that share corners with four equivalent O(1)Mg5 square pyramids, edges with four equivalent O(5)Mg6 octahedra, and edges with four equivalent O(3)RbMg5 octahedra. In the second O site, O(2) is bonded to one Mg(2) and four equivalent Mg(3) atoms to form distorted OMg5 square pyramids that share  a cornercorner with one O(3)RbMg5 octahedra, corners with four equivalent O(2)Mg5 square pyramids, and edges with four equivalent O(5)Mg6 octahedra. The corner-sharing octahedra are not tilted. In the third O site, O(3) is bonded to one Rb(1), one Mg(2), and four equivalent Mg(4) atoms to form distorted ORbMg5 octahedra that share corners with four equivalent O(3)RbMg5 octahedra,  a cornercorner with one O(2)Mg5 square pyramid, edges with four equivalent O(5)Mg6 octahedra, and edges with four equivalent O(1)Mg5 square pyramids. The corner-sharing octahedral tilt angles are 7°. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to two equivalent Rb(1), two equivalent Na(1), and one Mg(3) atom. In the fifth O site, O(5) is bonded to one Mg(3), one Mg(4), two equivalent Mg(1), and two equivalent Mg(2) atoms to form OMg6 octahedra that share corners with four equivalent O(5)Mg6 octahedra, edges with two equivalent O(3)RbMg5 octahedra, edges with four equivalent O(5)Mg6 octahedra, edges with two equivalent O(1)Mg5 square pyramids, and edges with two equivalent O(2)Mg5 square pyramids. The corner-sharing octahedral tilt angles range from 4-5°. is represented by the CIF file [CIF]
data_RbNaMg6O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.251
_cell_length_b   4.251
_cell_length_c   11.560
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   208.899
_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  0.500  0.967  1.0
  Na  Na1  1  0.000  0.000  0.066  1.0
  Mg  Mg2  1  0.000  0.000  0.496  1.0
  Mg  Mg3  1  0.500  0.500  0.481  1.0
  Mg  Mg4  1  0.000  0.500  0.270  1.0
  Mg  Mg5  1  0.000  0.500  0.670  1.0
  Mg  Mg6  1  0.500  0.000  0.270  1.0
  Mg  Mg7  1  0.500  0.000  0.670  1.0
  O  O8  1  0.000  0.000  0.680  1.0
  O  O9  1  0.500  0.500  0.308  1.0
  O  O10  1  0.500  0.500  0.681  1.0
  O  O11  1  0.000  0.500  0.106  1.0
  O  O12  1  0.000  0.500  0.489  1.0
  O  O13  1  0.500  0.000  0.106  1.0
  O  O14  1  0.500  0.000  0.489  1.0
[/CIF]
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The structure described by RbNaMg6O7 crystallizes in the tetragonal P4mm space group. Rb(1) is bonded in a 5-coordinate geometry to one O(3) and four equivalent O(4) atoms. Na(1) is bonded in a square co-planar geometry to four equivalent O(4) atoms. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(1) and four equivalent O(5) atoms to form MgO5 square pyramids that share corners with four equivalent Mg(1)O5 square pyramids, edges with four equivalent Mg(2)O6 octahedra, and edges with four equivalent Mg(4)O5 square pyramids. In the second Mg site, Mg(2) is bonded to one O(2), one O(3), and four equivalent O(5) atoms to form MgO6 octahedra that share corners with four equivalent Mg(2)O6 octahedra, edges with four equivalent Mg(1)O5 square pyramids, and edges with four equivalent Mg(4)O5 square pyramids. The corner-sharing octahedral tilt angles are 5°. In the third Mg site, Mg(3) is bonded in a 4-coordinate geometry to one O(4), one O(5), and two equivalent O(2) atoms. In the fourth Mg site, Mg(4) is bonded to one O(5), two equivalent O(1), and two equivalent O(3) atoms to form MgO5 square pyramids that share corners with four equivalent Mg(4)O5 square pyramids, edges with two equivalent Mg(2)O6 octahedra, edges with two equivalent Mg(1)O5 square pyramids, and edges with four equivalent Mg(4)O5 square pyramids. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1) and four equivalent Mg(4) atoms to form OMg5 square pyramids that share corners with four equivalent O(1)Mg5 square pyramids, edges with four equivalent O(5)Mg6 octahedra, and edges with four equivalent O(3)RbMg5 octahedra. In the second O site, O(2) is bonded to one Mg(2) and four equivalent Mg(3) atoms to form distorted OMg5 square pyramids that share  a cornercorner with one O(3)RbMg5 octahedra, corners with four equivalent O(2)Mg5 square pyramids, and edges with four equivalent O(5)Mg6 octahedra. The corner-sharing octahedra are not tilted. In the third O site, O(3) is bonded to one Rb(1), one Mg(2), and four equivalent Mg(4) atoms to form distorted ORbMg5 octahedra that share corners with four equivalent O(3)RbMg5 octahedra,  a cornercorner with one O(2)Mg5 square pyramid, edges with four equivalent O(5)Mg6 octahedra, and edges with four equivalent O(1)Mg5 square pyramids. The corner-sharing octahedral tilt angles are 7°. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to two equivalent Rb(1), two equivalent Na(1), and one Mg(3) atom. In the fifth O site, O(5) is bonded to one Mg(3), one Mg(4), two equivalent Mg(1), and two equivalent Mg(2) atoms to form OMg6 octahedra that share corners with four equivalent O(5)Mg6 octahedra, edges with two equivalent O(3)RbMg5 octahedra, edges with four equivalent O(5)Mg6 octahedra, edges with two equivalent O(1)Mg5 square pyramids, and edges with two equivalent O(2)Mg5 square pyramids. The corner-sharing octahedral tilt angles range from 4-5°. is represented by the CIF file [CIF]
data_RbNaMg6O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.251
_cell_length_b   4.251
_cell_length_c   11.560
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   208.899
_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  0.500  0.967  1.0
  Na  Na1  1  0.000  0.000  0.066  1.0
  Mg  Mg2  1  0.000  0.000  0.496  1.0
  Mg  Mg3  1  0.500  0.500  0.481  1.0
  Mg  Mg4  1  0.000  0.500  0.270  1.0
  Mg  Mg5  1  0.000  0.500  0.670  1.0
  Mg  Mg6  1  0.500  0.000  0.270  1.0
  Mg  Mg7  1  0.500  0.000  0.670  1.0
  O  O8  1  0.000  0.000  0.680  1.0
  O  O9  1  0.500  0.500  0.308  1.0
  O  O10  1  0.500  0.500  0.681  1.0
  O  O11  1  0.000  0.500  0.106  1.0
  O  O12  1  0.000  0.500  0.489  1.0
  O  O13  1  0.500  0.000  0.106  1.0
  O  O14  1  0.500  0.000  0.489  1.0
[/CIF]
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