The structure described by Pr2Fe16Al crystallizes in the trigonal R3m space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 19-coordinate geometry to one Fe(5), three equivalent Fe(2), three equivalent Fe(3), six equivalent Fe(1), and six equivalent Fe(4) atoms. In the second Pr site, Pr(2) is bonded in a 19-coordinate geometry to three equivalent Fe(2), three equivalent Fe(4), six equivalent Fe(1), six equivalent Fe(3), and one Al(1) atom. There are five inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 12-coordinate geometry to one Pr(1), one Pr(2), one Fe(5), two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(3), two equivalent Fe(4), and one Al(1) atom. In the second Fe site, Fe(2) is bonded to one Pr(1), one Pr(2), one Fe(5), two equivalent Fe(3), two equivalent Fe(4), four equivalent Fe(1), and one Al(1) atom to form distorted FePr2AlFe9 cuboctahedra that share corners with four equivalent Fe(2)Pr2AlFe9 cuboctahedra, corners with five equivalent Fe(3)Pr3AlFe8 cuboctahedra, corners with five equivalent Fe(4)Pr3Fe9 cuboctahedra, edges with three equivalent Fe(3)Pr3AlFe8 cuboctahedra, edges with three equivalent Fe(4)Pr3Fe9 cuboctahedra, faces with three equivalent Fe(3)Pr3AlFe8 cuboctahedra, faces with three equivalent Fe(4)Pr3Fe9 cuboctahedra, and faces with four equivalent Fe(2)Pr2AlFe9 cuboctahedra. In the third Fe site, Fe(3) is bonded to one Pr(1), two equivalent Pr(2), two equivalent Fe(2), two equivalent Fe(4), four equivalent Fe(1), and one Al(1) atom to form FePr3AlFe8 cuboctahedra that share corners with two equivalent Fe(3)Pr3AlFe8 cuboctahedra, corners with five equivalent Fe(2)Pr2AlFe9 cuboctahedra, corners with eight equivalent Fe(4)Pr3Fe9 cuboctahedra,  an edgeedge with one Fe(4)Pr3Fe9 cuboctahedra, edges with three equivalent Fe(2)Pr2AlFe9 cuboctahedra, edges with four equivalent Fe(3)Pr3AlFe8 cuboctahedra, faces with three equivalent Fe(2)Pr2AlFe9 cuboctahedra, faces with three equivalent Fe(4)Pr3Fe9 cuboctahedra, and faces with four equivalent Fe(3)Pr3AlFe8 cuboctahedra. In the fourth Fe site, Fe(4) is bonded to one Pr(2), two equivalent Pr(1), one Fe(5), two equivalent Fe(2), two equivalent Fe(3), and four equivalent Fe(1) atoms to form FePr3Fe9 cuboctahedra that share corners with two equivalent Fe(4)Pr3Fe9 cuboctahedra, corners with five equivalent Fe(2)Pr2AlFe9 cuboctahedra, corners with eight equivalent Fe(3)Pr3AlFe8 cuboctahedra,  an edgeedge with one Fe(3)Pr3AlFe8 cuboctahedra, edges with three equivalent Fe(2)Pr2AlFe9 cuboctahedra, edges with four equivalent Fe(4)Pr3Fe9 cuboctahedra, faces with three equivalent Fe(2)Pr2AlFe9 cuboctahedra, faces with three equivalent Fe(3)Pr3AlFe8 cuboctahedra, and faces with four equivalent Fe(4)Pr3Fe9 cuboctahedra. In the fifth Fe site, Fe(5) is bonded in a 14-coordinate geometry to one Pr(1), three equivalent Fe(2), three equivalent Fe(4), six equivalent Fe(1), and one Al(1) atom. Al(1) is bonded in a 14-coordinate geometry to one Pr(2), one Fe(5), three equivalent Fe(2), three equivalent Fe(3), and six equivalent Fe(1) atoms. is represented by the CIF card [CIF]
data_Pr2AlFe16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.472
_cell_length_b   6.472
_cell_length_c   6.472
_cell_angle_alpha   82.751
_cell_angle_beta   82.751
_cell_angle_gamma   82.751
_symmetry_Int_Tables_number   1
_cell_volume   265.115
_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  0.657  0.657  0.657  1.0
  Pr  Pr1  1  0.345  0.345  0.345  1.0
  Al  Al2  1  0.095  0.095  0.095  1.0
  Fe  Fe3  1  0.715  0.285  0.001  1.0
  Fe  Fe4  1  0.001  0.715  0.285  1.0
  Fe  Fe5  1  0.285  0.001  0.715  1.0
  Fe  Fe6  1  0.001  0.285  0.715  1.0
  Fe  Fe7  1  0.715  0.001  0.285  1.0
  Fe  Fe8  1  0.285  0.715  0.001  1.0
  Fe  Fe9  1  1.000  1.000  0.500  1.0
  Fe  Fe10  1  0.500  1.000  1.000  1.0
  Fe  Fe11  1  1.000  0.500  1.000  1.0
  Fe  Fe12  1  0.341  0.341  0.845  1.0
  Fe  Fe13  1  0.845  0.341  0.341  1.0
  Fe  Fe14  1  0.341  0.845  0.341  1.0
  Fe  Fe15  1  0.659  0.659  0.155  1.0
  Fe  Fe16  1  0.155  0.659  0.659  1.0
  Fe  Fe17  1  0.659  0.155  0.659  1.0
  Fe  Fe18  1  0.901  0.901  0.901  1.0
[/CIF]
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The structure described by Pr2Fe16Al crystallizes in the trigonal R3m space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 19-coordinate geometry to one Fe(5), three equivalent Fe(2), three equivalent Fe(3), six equivalent Fe(1), and six equivalent Fe(4) atoms. In the second Pr site, Pr(2) is bonded in a 19-coordinate geometry to three equivalent Fe(2), three equivalent Fe(4), six equivalent Fe(1), six equivalent Fe(3), and one Al(1) atom. There are five inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 12-coordinate geometry to one Pr(1), one Pr(2), one Fe(5), two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(3), two equivalent Fe(4), and one Al(1) atom. In the second Fe site, Fe(2) is bonded to one Pr(1), one Pr(2), one Fe(5), two equivalent Fe(3), two equivalent Fe(4), four equivalent Fe(1), and one Al(1) atom to form distorted FePr2AlFe9 cuboctahedra that share corners with four equivalent Fe(2)Pr2AlFe9 cuboctahedra, corners with five equivalent Fe(3)Pr3AlFe8 cuboctahedra, corners with five equivalent Fe(4)Pr3Fe9 cuboctahedra, edges with three equivalent Fe(3)Pr3AlFe8 cuboctahedra, edges with three equivalent Fe(4)Pr3Fe9 cuboctahedra, faces with three equivalent Fe(3)Pr3AlFe8 cuboctahedra, faces with three equivalent Fe(4)Pr3Fe9 cuboctahedra, and faces with four equivalent Fe(2)Pr2AlFe9 cuboctahedra. In the third Fe site, Fe(3) is bonded to one Pr(1), two equivalent Pr(2), two equivalent Fe(2), two equivalent Fe(4), four equivalent Fe(1), and one Al(1) atom to form FePr3AlFe8 cuboctahedra that share corners with two equivalent Fe(3)Pr3AlFe8 cuboctahedra, corners with five equivalent Fe(2)Pr2AlFe9 cuboctahedra, corners with eight equivalent Fe(4)Pr3Fe9 cuboctahedra,  an edgeedge with one Fe(4)Pr3Fe9 cuboctahedra, edges with three equivalent Fe(2)Pr2AlFe9 cuboctahedra, edges with four equivalent Fe(3)Pr3AlFe8 cuboctahedra, faces with three equivalent Fe(2)Pr2AlFe9 cuboctahedra, faces with three equivalent Fe(4)Pr3Fe9 cuboctahedra, and faces with four equivalent Fe(3)Pr3AlFe8 cuboctahedra. In the fourth Fe site, Fe(4) is bonded to one Pr(2), two equivalent Pr(1), one Fe(5), two equivalent Fe(2), two equivalent Fe(3), and four equivalent Fe(1) atoms to form FePr3Fe9 cuboctahedra that share corners with two equivalent Fe(4)Pr3Fe9 cuboctahedra, corners with five equivalent Fe(2)Pr2AlFe9 cuboctahedra, corners with eight equivalent Fe(3)Pr3AlFe8 cuboctahedra,  an edgeedge with one Fe(3)Pr3AlFe8 cuboctahedra, edges with three equivalent Fe(2)Pr2AlFe9 cuboctahedra, edges with four equivalent Fe(4)Pr3Fe9 cuboctahedra, faces with three equivalent Fe(2)Pr2AlFe9 cuboctahedra, faces with three equivalent Fe(3)Pr3AlFe8 cuboctahedra, and faces with four equivalent Fe(4)Pr3Fe9 cuboctahedra. In the fifth Fe site, Fe(5) is bonded in a 14-coordinate geometry to one Pr(1), three equivalent Fe(2), three equivalent Fe(4), six equivalent Fe(1), and one Al(1) atom. Al(1) is bonded in a 14-coordinate geometry to one Pr(2), one Fe(5), three equivalent Fe(2), three equivalent Fe(3), and six equivalent Fe(1) atoms. is represented by the CIF card [CIF]
data_Pr2AlFe16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.472
_cell_length_b   6.472
_cell_length_c   6.472
_cell_angle_alpha   82.751
_cell_angle_beta   82.751
_cell_angle_gamma   82.751
_symmetry_Int_Tables_number   1
_cell_volume   265.115
_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  0.657  0.657  0.657  1.0
  Pr  Pr1  1  0.345  0.345  0.345  1.0
  Al  Al2  1  0.095  0.095  0.095  1.0
  Fe  Fe3  1  0.715  0.285  0.001  1.0
  Fe  Fe4  1  0.001  0.715  0.285  1.0
  Fe  Fe5  1  0.285  0.001  0.715  1.0
  Fe  Fe6  1  0.001  0.285  0.715  1.0
  Fe  Fe7  1  0.715  0.001  0.285  1.0
  Fe  Fe8  1  0.285  0.715  0.001  1.0
  Fe  Fe9  1  1.000  1.000  0.500  1.0
  Fe  Fe10  1  0.500  1.000  1.000  1.0
  Fe  Fe11  1  1.000  0.500  1.000  1.0
  Fe  Fe12  1  0.341  0.341  0.845  1.0
  Fe  Fe13  1  0.845  0.341  0.341  1.0
  Fe  Fe14  1  0.341  0.845  0.341  1.0
  Fe  Fe15  1  0.659  0.659  0.155  1.0
  Fe  Fe16  1  0.155  0.659  0.659  1.0
  Fe  Fe17  1  0.659  0.155  0.659  1.0
  Fe  Fe18  1  0.901  0.901  0.901  1.0
[/CIF]
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