data_NaNi2Sn
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.22
_cell_length_b   3.22
_cell_length_c   6.72
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaNi2Sn
_chemical_formula_sum   'Na1 Ni2 Sn1'
_cell_volume   69.73
_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
  Na  Na0  1  0.0  0.0  0.0  1.0
  Ni  Ni1  1  0.61  0.61  0.04  1.0
  Ni  Ni2  1  0.61  0.61  0.68  1.0
  Sn  Sn3  1  0.0  0.0  0.36  1.0

data_NaNi2Sn
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.55
_cell_length_b   4.55
_cell_length_c   6.72
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   NaNi2Sn
_chemical_formula_sum   'Na2 Ni4 Sn2'
_cell_volume   139.45
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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
  Na  Na0  2  0.0  0.0  0.0  1.0
  Ni  Ni1  2  0.11  0.5  0.04  1.0
  Ni  Ni2  2  0.11  0.5  0.68  1.0
  Sn  Sn3  2  0.0  0.0  0.36  1.0

Na Ni Ni Sn
NaNi2Sn crystallizes in the monoclinic Cm space group. Na(1) is bonded in a 1-coordinate geometry to one Ni(1), four equivalent Ni(2), and one Sn(1) atom. The Na(1)-Ni(1) bond length is 1.80 Å. There are a spread of Na(1)-Ni(2) bond distances ranging from 2.77-3.50 Å. The Na(1)-Sn(1) bond length is 2.44 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 1-coordinate geometry to one Na(1) and one Ni(2) atom. The Ni(1)-Ni(2) bond length is 2.41 Å. In the second Ni site, Ni(2) is bonded in a 8-coordinate geometry to four equivalent Na(1), one Ni(1), and three equivalent Sn(1) atoms. There is one shorter (2.79 Å) and two longer (3.18 Å) Ni(2)-Sn(1) bond lengths. Sn(1) is bonded in a distorted single-bond geometry to one Na(1) and three equivalent Ni(2) atoms.