data_Nb2Ge
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.33
_cell_length_b   4.33
_cell_length_c   4.33
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Nb2Ge
_chemical_formula_sum   'Nb2 Ge1'
_cell_volume   57.53
_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  0.6  0.6  0.6  1.0
  Nb  Nb2  1  0.53  0.53  0.53  1.0
  Ge  Ge0  1  0.0  0.0  0.0  1.0

data_Nb2Ge
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.33
_cell_length_b   4.33
_cell_length_c   10.61
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Nb2Ge
_chemical_formula_sum   'Nb6 Ge3'
_cell_volume   172.6
_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  3  0.0  0.0  0.4  1.0
  Nb  Nb1  3  0.0  0.0  0.47  1.0
  Ge  Ge2  3  0.0  0.0  0.0  1.0

Nb Nb Ge
Nb2Ge crystallizes in the trigonal R3m space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one Nb(2) and three equivalent Ge(1) atoms to form distorted corner-sharing NbNbGe3 tetrahedra. The Nb(1)-Nb(2) bond length is 0.68 Å. All Nb(1)-Ge(1) bond lengths are 2.61 Å. In the second Nb site, Nb(2) is bonded in a single-bond geometry to one Nb(1) and three equivalent Ge(1) atoms. All Nb(2)-Ge(1) bond lengths are 3.27 Å. Ge(1) is bonded in a 6-coordinate geometry to three equivalent Nb(1) and three equivalent Nb(2) atoms.