data_Rb3NaCr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.18
_cell_length_b   7.18
_cell_length_c   7.18
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Rb3NaCr
_chemical_formula_sum   'Rb3 Na1 Cr1'
_cell_volume   370.89
_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  Rb1  1  0.0  0.59  0.0  1.0
  Rb  Rb2  1  0.0  0.0  0.59  1.0
  Rb  Rb3  1  0.59  0.0  0.0  1.0
  Na  Na4  1  0.0  0.0  0.0  1.0
  Cr  Cr0  1  0.59  0.59  0.59  1.0

data_Rb3NaCr
_symmetry_space_group_name_H-M   R3m
_cell_length_a   10.16
_cell_length_b   10.16
_cell_length_c   12.44
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Rb3NaCr
_chemical_formula_sum   'Rb9 Na3 Cr3'
_cell_volume   1112.66
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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  9  0.06  0.53  0.53  1.0
  Na  Na1  3  0.0  0.0  0.0  1.0
  Cr  Cr2  3  0.0  0.0  0.59  1.0

Rb Rb Rb Na Cr
Rb Rb Rb Na Cr 0 3 o + o 0 4 o o - 0 4 - o o 0 4 - o - 1 3 o o + 1 4 o - o 1 4 - o o 1 4 - - o 2 3 + o o 2 4 o o - 2 4 o - o 2 4 o - - 3 4 - - - 
Rb3NaCr crystallizes in the trigonal R3m space group. Rb(1) is bonded in a 3-coordinate geometry to two equivalent Na(1) and one Cr(1) atom. There is one shorter (2.93 Å) and one longer (4.26 Å) Rb(1)-Na(1) bond length. The Rb(1)-Cr(1) bond length is 4.14 Å. Na(1) is bonded to six equivalent Rb(1) atoms to form distorted corner-sharing NaRb6 octahedra. The corner-sharing octahedra are not tilted. Cr(1) is bonded in a 3-coordinate geometry to three equivalent Rb(1) atoms.