data_NiGe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.36
_cell_length_b   6.36
_cell_length_c   4.78
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   151.67
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NiGe2
_chemical_formula_sum   'Ni2 Ge4'
_cell_volume   91.73
_cell_formula_units_Z   2
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
  Ni  Ni4  1  0.56  0.54  0.58  1.0
  Ni  Ni5  1  0.56  0.46  0.19  1.0
  Ge  Ge0  1  0.56  0.22  0.58  1.0
  Ge  Ge1  1  0.56  0.46  0.58  1.0
  Ge  Ge2  1  0.56  0.54  0.19  1.0
  Ge  Ge3  1  0.56  0.78  0.19  1.0

data_NiGe2
_symmetry_space_group_name_H-M   P-1
_cell_length_a   3.11
_cell_length_b   4.78
_cell_length_c   6.36
_cell_angle_alpha   90.0
_cell_angle_beta   104.16
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   NiGe2
_chemical_formula_sum   'Ni2 Ge4'
_cell_volume   91.73
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-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
  Ni  Ni0  2  0.46  0.69  0.46  1.0
  Ge  Ge1  2  0.22  0.31  0.22  1.0
  Ge  Ge2  2  0.46  0.31  0.46  1.0

Ni Ni Ge Ge Ge Ge
Ni Ni Ge Ge Ge Ge 0 3 o o o 1 4 o o o 2 3 o o o 4 5 o o o 
NiGe2 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of two NiGe2 clusters. Ni(1) is bonded in a single-bond geometry to one Ge(2) atom. The Ni(1)-Ge(2) bond length is 0.51 Å. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded in a distorted single-bond geometry to one Ge(2) atom. The Ge(1)-Ge(2) bond length is 1.53 Å. In the second Ge site, Ge(2) is bonded in a single-bond geometry to one Ni(1) and one Ge(1) atom.