The material structure described by Pr4I5Ni crystallizes in the orthorhombic Pmmn space group. There are three inequivalent Pr sites. In the first Pr site, Pr(1) is bonded to one Ni(1), two equivalent I(1), and three equivalent I(2) atoms to form distorted PrNiI5 octahedra that share  a cornercorner with one Pr(2)Ni2I4 octahedra,  a cornercorner with one Pr(1)NiI5 octahedra, edges with two equivalent Pr(2)Ni2I4 octahedra, edges with two equivalent Pr(3)Ni2I4 octahedra, and edges with four equivalent Pr(1)NiI5 octahedra. The corner-sharing octahedral tilt angles range from 2-10°. In the second Pr site, Pr(2) is bonded to two equivalent Ni(1), two equivalent I(2), and two equivalent I(3) atoms to form PrNi2I4 octahedra that share corners with two equivalent Pr(1)NiI5 octahedra, corners with four equivalent Pr(3)Ni2I4 octahedra, edges with two equivalent Pr(2)Ni2I4 octahedra, edges with two equivalent Pr(3)Ni2I4 octahedra, and edges with four equivalent Pr(1)NiI5 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the third Pr site, Pr(3) is bonded to two equivalent Ni(1), two equivalent I(1), and two equivalent I(3) atoms to form PrNi2I4 octahedra that share corners with four equivalent Pr(2)Ni2I4 octahedra, edges with two equivalent Pr(2)Ni2I4 octahedra, edges with two equivalent Pr(3)Ni2I4 octahedra, and edges with four equivalent Pr(1)NiI5 octahedra. The corner-sharing octahedra are not tilted. Ni(1) is bonded to two equivalent Pr(1), two equivalent Pr(2), and two equivalent Pr(3) atoms to form edge-sharing NiPr6 octahedra. There are three inequivalent I sites. In the first I site, I(1) is bonded in a 3-coordinate geometry to one Pr(3) and two equivalent Pr(1) atoms. In the second I site, I(2) is bonded in a distorted see-saw-like geometry to one Pr(2) and three equivalent Pr(1) atoms. In the third I site, I(3) is bonded in a square co-planar geometry to two equivalent Pr(2) and two equivalent Pr(3) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Pr4NiI5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.217
_cell_length_b   9.165
_cell_length_c   19.210
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   742.420
_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  Pr0  1  0.000  0.371  0.855  1.0
  Pr  Pr1  1  0.500  0.581  0.000  1.0
  Pr  Pr2  1  0.000  0.371  0.145  1.0
  Pr  Pr3  1  0.000  0.834  0.500  1.0
  Pr  Pr4  1  0.500  0.629  0.355  1.0
  Pr  Pr5  1  0.000  0.419  0.500  1.0
  Pr  Pr6  1  0.500  0.629  0.645  1.0
  Pr  Pr7  1  0.500  0.166  0.000  1.0
  Ni  Ni8  1  0.500  0.625  0.500  1.0
  Ni  Ni9  1  0.000  0.375  0.000  1.0
  I  I10  1  0.500  0.109  0.169  1.0
  I  I11  1  0.000  0.362  0.674  1.0
  I  I12  1  0.000  0.873  0.000  1.0
  I  I13  1  0.000  0.891  0.331  1.0
  I  I14  1  0.500  0.109  0.831  1.0
  I  I15  1  0.500  0.638  0.826  1.0
  I  I16  1  0.000  0.891  0.669  1.0
  I  I17  1  0.000  0.362  0.326  1.0
  I  I18  1  0.500  0.638  0.174  1.0
  I  I19  1  0.500  0.127  0.500  1.0
[/CIF]
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The material structure described by Pr4I5Ni crystallizes in the orthorhombic Pmmn space group. There are three inequivalent Pr sites. In the first Pr site, Pr(1) is bonded to one Ni(1), two equivalent I(1), and three equivalent I(2) atoms to form distorted PrNiI5 octahedra that share  a cornercorner with one Pr(2)Ni2I4 octahedra,  a cornercorner with one Pr(1)NiI5 octahedra, edges with two equivalent Pr(2)Ni2I4 octahedra, edges with two equivalent Pr(3)Ni2I4 octahedra, and edges with four equivalent Pr(1)NiI5 octahedra. The corner-sharing octahedral tilt angles range from 2-10°. In the second Pr site, Pr(2) is bonded to two equivalent Ni(1), two equivalent I(2), and two equivalent I(3) atoms to form PrNi2I4 octahedra that share corners with two equivalent Pr(1)NiI5 octahedra, corners with four equivalent Pr(3)Ni2I4 octahedra, edges with two equivalent Pr(2)Ni2I4 octahedra, edges with two equivalent Pr(3)Ni2I4 octahedra, and edges with four equivalent Pr(1)NiI5 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the third Pr site, Pr(3) is bonded to two equivalent Ni(1), two equivalent I(1), and two equivalent I(3) atoms to form PrNi2I4 octahedra that share corners with four equivalent Pr(2)Ni2I4 octahedra, edges with two equivalent Pr(2)Ni2I4 octahedra, edges with two equivalent Pr(3)Ni2I4 octahedra, and edges with four equivalent Pr(1)NiI5 octahedra. The corner-sharing octahedra are not tilted. Ni(1) is bonded to two equivalent Pr(1), two equivalent Pr(2), and two equivalent Pr(3) atoms to form edge-sharing NiPr6 octahedra. There are three inequivalent I sites. In the first I site, I(1) is bonded in a 3-coordinate geometry to one Pr(3) and two equivalent Pr(1) atoms. In the second I site, I(2) is bonded in a distorted see-saw-like geometry to one Pr(2) and three equivalent Pr(1) atoms. In the third I site, I(3) is bonded in a square co-planar geometry to two equivalent Pr(2) and two equivalent Pr(3) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Pr4NiI5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.217
_cell_length_b   9.165
_cell_length_c   19.210
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   742.420
_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  Pr0  1  0.000  0.371  0.855  1.0
  Pr  Pr1  1  0.500  0.581  0.000  1.0
  Pr  Pr2  1  0.000  0.371  0.145  1.0
  Pr  Pr3  1  0.000  0.834  0.500  1.0
  Pr  Pr4  1  0.500  0.629  0.355  1.0
  Pr  Pr5  1  0.000  0.419  0.500  1.0
  Pr  Pr6  1  0.500  0.629  0.645  1.0
  Pr  Pr7  1  0.500  0.166  0.000  1.0
  Ni  Ni8  1  0.500  0.625  0.500  1.0
  Ni  Ni9  1  0.000  0.375  0.000  1.0
  I  I10  1  0.500  0.109  0.169  1.0
  I  I11  1  0.000  0.362  0.674  1.0
  I  I12  1  0.000  0.873  0.000  1.0
  I  I13  1  0.000  0.891  0.331  1.0
  I  I14  1  0.500  0.109  0.831  1.0
  I  I15  1  0.500  0.638  0.826  1.0
  I  I16  1  0.000  0.891  0.669  1.0
  I  I17  1  0.000  0.362  0.326  1.0
  I  I18  1  0.500  0.638  0.174  1.0
  I  I19  1  0.500  0.127  0.500  1.0
[/CIF]
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