data_Si2NiSn
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.56
_cell_length_b   5.56
_cell_length_c   3.54
_cell_angle_alpha   108.16
_cell_angle_beta   108.16
_cell_angle_gamma   126.09
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2NiSn
_chemical_formula_sum   'Si2 Ni1 Sn1'
_cell_volume   64.19
_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
  Si  Si1  1  0.26  0.48  0.0  1.0
  Si  Si2  1  0.26  0.52  0.0  1.0
  Ni  Ni0  1  0.0  0.0  0.0  1.0
  Sn  Sn3  1  0.52  0.0  0.0  1.0

data_Si2NiSn
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.54
_cell_length_b   3.66
_cell_length_c   5.56
_cell_angle_alpha   108.8
_cell_angle_beta   108.16
_cell_angle_gamma   91.24
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2NiSn
_chemical_formula_sum   'Si2 Ni1 Sn1'
_cell_volume   64.19
_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
  Si  Si0  1  0.48  0.48  0.74  1.0
  Si  Si1  1  0.52  0.52  0.78  1.0
  Ni  Ni2  1  0.0  0.0  0.0  1.0
  Sn  Sn3  1  0.0  0.0  0.52  1.0

Si Si Ni Sn
NiSnSi2 crystallizes in the triclinic P1 space group. Ni(1) is bonded in a 5-coordinate geometry to two equivalent Sn(1) and three equivalent Si(1) atoms. There is one shorter (2.67 Å) and one longer (2.88 Å) Ni(1)-Sn(1) bond length. There are a spread of Ni(1)-Si(1) bond distances ranging from 2.14-2.89 Å. Sn(1) is bonded in a 1-coordinate geometry to two equivalent Ni(1) and one Si(2) atom. The Sn(1)-Si(2) bond length is 2.14 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a single-bond geometry to three equivalent Ni(1) and one Si(2) atom. The Si(1)-Si(2) bond length is 0.26 Å. In the second Si site, Si(2) is bonded in a distorted single-bond geometry to one Sn(1) and one Si(1) atom.