The material structure described by Rb3MgNbO8 crystallizes in the monoclinic C2 space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent O(3) and two equivalent O(4) atoms. In the second Rb site, Rb(2) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. Mg(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted MgO6 octahedra that share faces with two equivalent Nb(1)O8 hexagonal bipyramids. Nb(1) is bonded to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted NbO8 hexagonal bipyramids that share faces with two equivalent Mg(1)O6 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Rb(2), one Mg(1), and one Nb(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Rb(2), one Nb(1), and one O(3) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Rb(1), one Rb(2), one Mg(1), one Nb(1), and one O(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Rb(1), two equivalent Rb(2), one Mg(1), and one Nb(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Rb3MgNbO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.572
_cell_length_b   7.127
_cell_length_c   7.572
_cell_angle_alpha   78.614
_cell_angle_beta   123.148
_cell_angle_gamma   132.755
_symmetry_Int_Tables_number   1
_cell_volume   240.957
_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  0.015  0.500  0.515  1.0
  Rb  Rb1  1  0.454  0.767  0.264  1.0
  Rb  Rb2  1  0.497  0.233  0.688  1.0
  Mg  Mg3  1  0.564  0.500  0.064  1.0
  Nb  Nb4  1  0.039  0.000  0.039  1.0
  O  O5  1  0.351  0.103  0.006  1.0
  O  O6  1  0.903  0.897  0.247  1.0
  O  O7  1  0.965  0.239  0.990  1.0
  O  O8  1  0.751  0.761  0.726  1.0
  O  O9  1  0.548  0.659  0.786  1.0
  O  O10  1  0.127  0.341  0.889  1.0
  O  O11  1  0.977  0.693  0.152  1.0
  O  O12  1  0.459  0.307  0.284  1.0
[/CIF]
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The material structure described by Rb3MgNbO8 crystallizes in the monoclinic C2 space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent O(3) and two equivalent O(4) atoms. In the second Rb site, Rb(2) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. Mg(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted MgO6 octahedra that share faces with two equivalent Nb(1)O8 hexagonal bipyramids. Nb(1) is bonded to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted NbO8 hexagonal bipyramids that share faces with two equivalent Mg(1)O6 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Rb(2), one Mg(1), and one Nb(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Rb(2), one Nb(1), and one O(3) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Rb(1), one Rb(2), one Mg(1), one Nb(1), and one O(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Rb(1), two equivalent Rb(2), one Mg(1), and one Nb(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Rb3MgNbO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.572
_cell_length_b   7.127
_cell_length_c   7.572
_cell_angle_alpha   78.614
_cell_angle_beta   123.148
_cell_angle_gamma   132.755
_symmetry_Int_Tables_number   1
_cell_volume   240.957
_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  0.015  0.500  0.515  1.0
  Rb  Rb1  1  0.454  0.767  0.264  1.0
  Rb  Rb2  1  0.497  0.233  0.688  1.0
  Mg  Mg3  1  0.564  0.500  0.064  1.0
  Nb  Nb4  1  0.039  0.000  0.039  1.0
  O  O5  1  0.351  0.103  0.006  1.0
  O  O6  1  0.903  0.897  0.247  1.0
  O  O7  1  0.965  0.239  0.990  1.0
  O  O8  1  0.751  0.761  0.726  1.0
  O  O9  1  0.548  0.659  0.786  1.0
  O  O10  1  0.127  0.341  0.889  1.0
  O  O11  1  0.977  0.693  0.152  1.0
  O  O12  1  0.459  0.307  0.284  1.0
[/CIF]
.