data_HfNb4Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.49
_cell_length_b   5.49
_cell_length_c   5.49
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HfNb4Se
_chemical_formula_sum   'Hf1 Nb4 Se1'
_cell_volume   117.17
_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  Hf0  1  0.94  0.94  0.94  1.0
  Nb  Nb1  1  0.92  0.92  0.85  1.0
  Nb  Nb2  1  0.92  0.85  0.92  1.0
  Nb  Nb3  1  0.85  0.92  0.92  1.0
  Nb  Nb4  1  0.85  0.85  0.85  1.0
  Se  Se5  1  0.0  0.0  0.0  1.0

data_HfNb4Se
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.49
_cell_length_b   5.49
_cell_length_c   13.45
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   HfNb4Se
_chemical_formula_sum   'Hf3 Nb12 Se3'
_cell_volume   351.51
_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  0.06  1.0
  Nb  Nb1  9  0.05  0.02  0.1  1.0
  Nb  Nb2  3  0.0  0.0  0.15  1.0
  Se  Se3  3  0.0  0.0  -0.0  1.0

Hf Nb Nb Nb Nb Se
Hf Nb Nb Nb Nb Se 0 3 o o o 0 2 o o o 0 1 o o o 0 5 + + + 1 2 o o o 1 3 o o o 1 4 o o o 2 3 o o o 2 4 o o o 3 4 o o o 
HfNb4Se is Copper structured and crystallizes in the trigonal R3m space group. The structure is zero-dimensional and consists of three HfNb4Se clusters. Hf(1) is bonded in a distorted single-bond geometry to three equivalent Nb(1) and one Se(1) atom. All Hf(1)-Nb(1) bond lengths are 0.66 Å. The Hf(1)-Se(1) bond length is 0.78 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 4-coordinate geometry to one Hf(1), one Nb(2), and two equivalent Nb(1) atoms. The Nb(1)-Nb(2) bond length is 0.67 Å. Both Nb(1)-Nb(1) bond lengths are 0.39 Å. In the second Nb site, Nb(2) is bonded in a 3-coordinate geometry to three equivalent Nb(1) atoms. Se(1) is bonded in a single-bond geometry to one Hf(1) atom.