data_PrN2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.51
_cell_length_b   5.51
_cell_length_c   3.95
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   PrN2
_chemical_formula_sum   'Pr2 N4'
_cell_volume   120.02
_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
  Pr  Pr4  1  0.0  0.0  0.0  1.0
  Pr  Pr5  1  0.76  0.76  0.98  1.0
  N  N0  1  0.72  0.72  0.0  1.0
  N  N1  1  0.79  0.79  0.0  1.0
  N  N2  1  0.48  0.03  0.98  1.0
  N  N3  1  0.03  0.48  0.98  1.0

data_PrN2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   7.8
_cell_length_b   7.8
_cell_length_c   3.95
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   PrN2
_chemical_formula_sum   'Pr4 N8'
_cell_volume   240.05
_cell_formula_units_Z   4
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
  Pr  Pr1  2  0.26  0.5  0.98  1.0
  N  N2  4  0.26  0.22  0.98  1.0
  N  N3  2  0.22  0.5  0.0  1.0
  N  N4  2  0.29  0.5  0.0  1.0

Pr Pr N N N N
PrN2 crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two PrN2 clusters. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a distorted single-bond geometry to one N(2) and two equivalent N(3) atoms. The Pr(1)-N(2) bond length is 1.64 Å. Both Pr(1)-N(3) bond lengths are 2.65 Å. In the second Pr site, Pr(2) is bonded in a bent 150 degrees geometry to one N(1) and one N(2) atom. The Pr(2)-N(1) bond length is 0.28 Å. The Pr(2)-N(2) bond length is 0.28 Å. There are three inequivalent N sites. In the first N site, N(1) is bonded in a single-bond geometry to one Pr(2) atom. In the second N site, N(2) is bonded in a single-bond geometry to one Pr(1) and one Pr(2) atom. In the third N site, N(3) is bonded in a distorted single-bond geometry to one Pr(1) atom.