data_Nb3AgI
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.03
_cell_length_b   5.03
_cell_length_c   5.03
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Nb3AgI
_chemical_formula_sum   'Nb3 Ag1 I1'
_cell_volume   127.26
_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
  Nb  Nb1  1  0.51  0.0  0.51  1.0
  Nb  Nb2  1  0.51  0.51  0.0  1.0
  Nb  Nb3  1  0.0  0.51  0.51  1.0
  Ag  Ag4  1  0.0  0.0  0.0  1.0
  I  I0  1  0.51  0.51  0.51  1.0

data_Nb3AgI
_symmetry_space_group_name_H-M   R3m
_cell_length_a   7.11
_cell_length_b   7.11
_cell_length_c   8.71
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Nb3AgI
_chemical_formula_sum   'Nb9 Ag3 I3'
_cell_volume   381.78
_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
  Nb  Nb0  9  0.17  0.34  0.34  1.0
  Ag  Ag1  3  0.0  0.0  0.0  1.0
  I  I2  3  0.0  0.0  0.51  1.0

Nb Nb Nb Ag I
Nb Nb Nb Ag I 0 4 o - o 0 4 o o o 0 3 + o + 0 3 + o o 0 3 o o + 0 3 o o o 1 4 o o - 1 4 o o o 1 3 + + o 1 3 + o o 1 3 o + o 1 3 o o o 2 4 - o o 2 4 o o o 2 3 o + + 2 3 o + o 2 3 o o + 2 3 o o o 3 4 - - - 
Nb3AgI is (Cubic) Perovskite structured and crystallizes in the trigonal R3m space group. Nb(1) is bonded in a linear geometry to four equivalent Ag(1) and two equivalent I(1) atoms. There are a spread of Nb(1)-Ag(1) bond distances ranging from 3.45-3.66 Å. There is one shorter (2.44 Å) and one longer (2.59 Å) Nb(1)-I(1) bond length. Ag(1) is bonded to twelve equivalent Nb(1) atoms to form AgNb12 cuboctahedra that share corners with twelve equivalent Ag(1)Nb12 cuboctahedra, faces with six equivalent Ag(1)Nb12 cuboctahedra, and faces with eight equivalent I(1)Nb6 octahedra. I(1) is bonded to six equivalent Nb(1) atoms to form INb6 octahedra that share corners with six equivalent I(1)Nb6 octahedra and faces with eight equivalent Ag(1)Nb12 cuboctahedra. The corner-sharing octahedra are not tilted.