data_HfNb3Ag
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.92
_cell_length_b   4.92
_cell_length_c   4.92
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HfNb3Ag
_chemical_formula_sum   'Hf1 Nb3 Ag1'
_cell_volume   118.92
_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
  Hf  Hf3  1  0.46  0.46  0.46  1.0
  Nb  Nb0  1  0.46  0.0  0.46  1.0
  Nb  Nb1  1  0.46  0.46  0.0  1.0
  Nb  Nb2  1  0.0  0.46  0.46  1.0
  Ag  Ag4  1  0.0  0.0  0.0  1.0

data_HfNb3Ag
_symmetry_space_group_name_H-M   R3m
_cell_length_a   6.95
_cell_length_b   6.95
_cell_length_c   8.52
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   HfNb3Ag
_chemical_formula_sum   'Hf3 Nb9 Ag3'
_cell_volume   356.75
_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
  Hf  Hf0  3  0.0  0.0  0.46  1.0
  Nb  Nb1  9  0.03  0.51  0.97  1.0
  Ag  Ag2  3  0.0  0.0  0.0  1.0

Hf Nb Nb Nb Ag
Hf Nb Nb Nb Ag 0 3 o o o 0 3 + o o 0 1 o o o 0 1 o + o 0 2 o o o 0 2 o o + 0 4 o o o 1 4 + o + 1 4 + o o 1 4 o o + 1 4 o o o 2 4 + + o 2 4 + o o 2 4 o + o 2 4 o o o 3 4 o + + 3 4 o + o 3 4 o o + 3 4 o o o 
HfNb3Ag is (Cubic) Perovskite structured and crystallizes in the trigonal R3m space group. Hf(1) is bonded to six equivalent Nb(1) atoms to form HfNb6 octahedra that share corners with six equivalent Hf(1)Nb6 octahedra and faces with eight equivalent Ag(1)Nb12 cuboctahedra. The corner-sharing octahedra are not tilted. There are three shorter (2.26 Å) and three longer (2.66 Å) Hf(1)-Nb(1) bond lengths. Nb(1) is bonded in a 2-coordinate geometry to two equivalent Hf(1) and four equivalent Ag(1) atoms. There are a spread of Nb(1)-Ag(1) bond distances ranging from 3.19-3.76 Å. Ag(1) is bonded to twelve equivalent Nb(1) atoms to form distorted 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 Hf(1)Nb6 octahedra.