data_Si2Ni
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.25
_cell_length_b   4.25
_cell_length_c   4.65
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   67.42
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2Ni
_chemical_formula_sum   'Si4 Ni2'
_cell_volume   77.4
_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
  Si  Si2  1  0.34  0.14  0.16  1.0
  Si  Si3  1  0.72  0.86  0.49  1.0
  Si  Si4  1  0.72  0.14  0.16  1.0
  Si  Si5  1  0.34  0.86  0.49  1.0
  Ni  Ni0  1  0.53  0.65  0.16  1.0
  Ni  Ni1  1  0.53  0.35  0.49  1.0

data_Si2Ni
_symmetry_space_group_name_H-M   P-1
_cell_length_a   4.25
_cell_length_b   4.25
_cell_length_c   4.65
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   112.58
_symmetry_Int_Tables_number   2
_chemical_formula_structural   Si2Ni
_chemical_formula_sum   'Si4 Ni2'
_cell_volume   77.4
_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
  Si  Si0  2  0.31  0.14  0.34  1.0
  Si  Si1  2  0.31  0.86  0.66  1.0
  Ni  Ni2  2  0.5  0.35  0.66  1.0

Si Si Si Si Ni Ni
Si Si Si Si Ni Ni 0 3 o - o 0 4 o - o 0 5 o o o 0 2 o o o 1 4 o o o 1 5 o + o 1 3 o o o 1 2 o + o 2 5 o o o 2 4 o o o 3 5 o o o 3 4 o o o 4 5 o o o 