data_Cs2PrNb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.18
_cell_length_b   6.18
_cell_length_c   6.18
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Cs2PrNb
_chemical_formula_sum   'Cs2 Pr1 Nb1'
_cell_volume   167.21
_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
  Cs  Cs0  1  0.19  0.19  0.19  1.0
  Cs  Cs1  1  0.56  0.56  0.56  1.0
  Pr  Pr3  1  0.37  0.37  0.37  1.0
  Nb  Nb2  1  0.0  0.0  0.0  1.0

data_Cs2PrNb
_symmetry_space_group_name_H-M   R3m
_cell_length_a   6.18
_cell_length_b   6.18
_cell_length_c   15.15
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Cs2PrNb
_chemical_formula_sum   'Cs6 Pr3 Nb3'
_cell_volume   501.64
_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
  Cs  Cs0  3  0.0  0.0  0.44  1.0
  Cs  Cs1  3  0.0  0.0  0.81  1.0
  Pr  Pr2  3  0.0  0.0  0.63  1.0
  Nb  Nb3  3  0.0  0.0  0.0  1.0

Cs Cs Pr Nb
Cs Cs Pr Nb 0 3 o o o 0 2 o o o 0 1 o o - 0 1 o - o 0 1 - o o 1 2 o o o 2 3 + o o 2 3 o + o 2 3 o o + 
Cs2PrNb crystallizes in the trigonal R3m space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a linear geometry to one Pr(1) and one Nb(1) atom. The Cs(1)-Pr(1) bond length is 2.82 Å. The Cs(1)-Nb(1) bond length is 2.82 Å. In the second Cs site, Cs(2) is bonded in a 1-coordinate geometry to one Pr(1) atom. The Cs(2)-Pr(1) bond length is 2.82 Å. Pr(1) is bonded in a 5-coordinate geometry to one Cs(1), one Cs(2), and three equivalent Nb(1) atoms. All Pr(1)-Nb(1) bond lengths are 3.62 Å. Nb(1) is bonded in a distorted single-bond geometry to one Cs(1) and three equivalent Pr(1) atoms.