data_Pr(NiSn)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.13
_cell_length_b   6.13
_cell_length_c   6.13
_cell_angle_alpha   137.61
_cell_angle_beta   137.61
_cell_angle_gamma   61.51
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Pr(NiSn)2
_chemical_formula_sum   'Pr1 Ni2 Sn2'
_cell_volume   103.76
_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
  Pr  Pr0  1  0.0  0.0  0.0  1.0
  Ni  Ni1  1  0.0  0.22  0.64  1.0
  Ni  Ni2  1  0.22  0.0  0.64  1.0
  Sn  Sn3  1  0.0  0.0  0.84  1.0
  Sn  Sn4  1  0.0  0.0  0.71  1.0

data_Pr(NiSn)2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.27
_cell_length_b   6.27
_cell_length_c   6.13
_cell_angle_alpha   90.0
_cell_angle_beta   120.75
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Pr(NiSn)2
_chemical_formula_sum   'Pr2 Ni4 Sn4'
_cell_volume   207.52
_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
  Pr  Pr0  2  0.0  0.0  0.0  1.0
  Ni  Ni1  4  0.39  0.39  0.42  1.0
  Sn  Sn2  2  0.0  0.0  0.71  1.0
  Sn  Sn3  2  0.0  0.0  0.84  1.0

Pr Ni Ni Sn Sn
Pr(NiSn)2 crystallizes in the monoclinic Cm space group. Pr(1) is bonded in a single-bond geometry to four equivalent Ni(1) and one Sn(1) atom. There are two shorter (3.05 Å) and two longer (3.49 Å) Pr(1)-Ni(1) bond lengths. The Pr(1)-Sn(1) bond length is 0.99 Å. Ni(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Pr(1), one Ni(1), and one Sn(2) atom. The Ni(1)-Ni(1) bond length is 1.37 Å. The Ni(1)-Sn(2) bond length is 1.68 Å. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a distorted linear geometry to one Pr(1) and one Sn(2) atom. The Sn(1)-Sn(2) bond length is 0.81 Å. In the second Sn site, Sn(2) is bonded in a 3-coordinate geometry to two equivalent Ni(1) and one Sn(1) atom.