data_FeSi2Ni
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.54
_cell_length_b   4.54
_cell_length_c   4.54
_cell_angle_alpha   136.21
_cell_angle_beta   136.21
_cell_angle_gamma   63.66
_symmetry_Int_Tables_number   1
_chemical_formula_structural   FeSi2Ni
_chemical_formula_sum   'Fe1 Si2 Ni1'
_cell_volume   44.22
_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
  Fe  Fe0  1  0.0  0.0  0.86  1.0
  Si  Si2  1  0.0  0.0  0.0  1.0
  Si  Si3  1  0.69  0.0  0.93  1.0
  Ni  Ni1  1  0.0  0.69  0.93  1.0

data_FeSi2Ni
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.39
_cell_length_b   3.39
_cell_length_c   4.54
_cell_angle_alpha   111.9
_cell_angle_beta   111.9
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   FeSi2Ni
_chemical_formula_sum   'Fe1 Si2 Ni1'
_cell_volume   44.22
_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
  Fe  Fe0  1  0.14  0.0  0.14  1.0
  Si  Si1  1  0.0  0.0  0.0  1.0
  Si  Si2  1  0.07  0.0  0.76  1.0
  Ni  Ni3  1  0.76  0.69  0.76  1.0

Fe Si Si Ni
FeNiSi2 crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one FeNiSi2 cluster. Fe(1) is bonded in a single-bond geometry to one Si(1) atom. The Fe(1)-Si(1) bond length is 0.65 Å. Ni(1) is bonded in a distorted single-bond geometry to one Si(1) atom. The Ni(1)-Si(1) bond length is 1.18 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 3-coordinate geometry to one Fe(1), one Ni(1), and one Si(2) atom. The Si(1)-Si(2) bond length is 1.18 Å. In the second Si site, Si(2) is bonded in a 1-coordinate geometry to one Si(1) atom.