The material described by Pr2Ni7 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 12-coordinate geometry to three equivalent Ni(1) and nine equivalent Ni(3) atoms. In the second Pr site, Pr(2) is bonded in a 18-coordinate geometry to three equivalent Ni(4), three equivalent Ni(5), six equivalent Ni(2), and six equivalent Ni(3) atoms. There are five inequivalent Ni sites. In the first Ni site, Ni(5) is bonded in a 9-coordinate geometry to three equivalent Pr(2), three equivalent Ni(2), and three equivalent Ni(3) atoms. In the second Ni site, Ni(1) is bonded to six equivalent Pr(1) and six equivalent Ni(3) atoms to form NiPr6Ni6 cuboctahedra that share corners with twelve equivalent Ni(3)Pr5Ni7 cuboctahedra, edges with six equivalent Ni(1)Pr6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(3)Pr5Ni7 cuboctahedra. In the third Ni site, Ni(2) is bonded to four equivalent Pr(2), two equivalent Ni(4), two equivalent Ni(5), and four equivalent Ni(2) atoms to form NiPr4Ni8 cuboctahedra that share corners with four equivalent Ni(2)Pr4Ni8 cuboctahedra, corners with twelve equivalent Ni(3)Pr5Ni7 cuboctahedra, edges with two equivalent Ni(2)Pr4Ni8 cuboctahedra, edges with eight equivalent Ni(3)Pr5Ni7 cuboctahedra, faces with two equivalent Ni(3)Pr5Ni7 cuboctahedra, and faces with eight equivalent Ni(2)Pr4Ni8 cuboctahedra. In the fourth Ni site, Ni(3) is bonded to two equivalent Pr(2), three equivalent Pr(1), one Ni(1), one Ni(4), one Ni(5), and four equivalent Ni(3) atoms to form distorted NiPr5Ni7 cuboctahedra that share corners with two equivalent Ni(1)Pr6Ni6 cuboctahedra, corners with six equivalent Ni(2)Pr4Ni8 cuboctahedra, corners with nine equivalent Ni(3)Pr5Ni7 cuboctahedra, edges with four equivalent Ni(2)Pr4Ni8 cuboctahedra, edges with four equivalent Ni(3)Pr5Ni7 cuboctahedra,  a faceface with one Ni(2)Pr4Ni8 cuboctahedra, faces with three equivalent Ni(1)Pr6Ni6 cuboctahedra, and faces with ten equivalent Ni(3)Pr5Ni7 cuboctahedra. In the fifth Ni site, Ni(4) is bonded in a 9-coordinate geometry to three equivalent Pr(2), three equivalent Ni(2), and three equivalent Ni(3) atoms. is represented by the CIF card [CIF]
data_Pr2Ni7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.066
_cell_length_b   5.066
_cell_length_c   24.670
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   548.331
_cell_formula_units_Z   4
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  0.333  0.667  0.470  1.0
  Pr  Pr1  1  0.667  0.333  0.530  1.0
  Pr  Pr2  1  0.667  0.333  0.970  1.0
  Pr  Pr3  1  0.333  0.667  0.030  1.0
  Pr  Pr4  1  0.333  0.667  0.326  1.0
  Pr  Pr5  1  0.667  0.333  0.674  1.0
  Pr  Pr6  1  0.667  0.333  0.826  1.0
  Pr  Pr7  1  0.333  0.667  0.174  1.0
  Ni  Ni8  1  0.000  0.000  0.500  1.0
  Ni  Ni9  1  0.000  0.000  0.000  1.0
  Ni  Ni10  1  0.833  0.167  0.250  1.0
  Ni  Ni11  1  0.833  0.666  0.250  1.0
  Ni  Ni12  1  0.334  0.167  0.250  1.0
  Ni  Ni13  1  0.167  0.833  0.750  1.0
  Ni  Ni14  1  0.167  0.334  0.750  1.0
  Ni  Ni15  1  0.666  0.833  0.750  1.0
  Ni  Ni16  1  0.834  0.166  0.412  1.0
  Ni  Ni17  1  0.834  0.668  0.412  1.0
  Ni  Ni18  1  0.332  0.166  0.412  1.0
  Ni  Ni19  1  0.166  0.834  0.588  1.0
  Ni  Ni20  1  0.166  0.332  0.588  1.0
  Ni  Ni21  1  0.668  0.834  0.588  1.0
  Ni  Ni22  1  0.166  0.834  0.912  1.0
  Ni  Ni23  1  0.166  0.332  0.912  1.0
  Ni  Ni24  1  0.668  0.834  0.912  1.0
  Ni  Ni25  1  0.834  0.166  0.088  1.0
  Ni  Ni26  1  0.834  0.668  0.088  1.0
  Ni  Ni27  1  0.332  0.166  0.088  1.0
  Ni  Ni28  1  0.000  0.000  0.331  1.0
  Ni  Ni29  1  0.000  0.000  0.669  1.0
  Ni  Ni30  1  0.000  0.000  0.831  1.0
  Ni  Ni31  1  0.000  0.000  0.169  1.0
  Ni  Ni32  1  0.333  0.667  0.668  1.0
  Ni  Ni33  1  0.667  0.333  0.332  1.0
  Ni  Ni34  1  0.667  0.333  0.168  1.0
  Ni  Ni35  1  0.333  0.667  0.832  1.0
[/CIF]
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The material described by Pr2Ni7 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 12-coordinate geometry to three equivalent Ni(1) and nine equivalent Ni(3) atoms. In the second Pr site, Pr(2) is bonded in a 18-coordinate geometry to three equivalent Ni(4), three equivalent Ni(5), six equivalent Ni(2), and six equivalent Ni(3) atoms. There are five inequivalent Ni sites. In the first Ni site, Ni(5) is bonded in a 9-coordinate geometry to three equivalent Pr(2), three equivalent Ni(2), and three equivalent Ni(3) atoms. In the second Ni site, Ni(1) is bonded to six equivalent Pr(1) and six equivalent Ni(3) atoms to form NiPr6Ni6 cuboctahedra that share corners with twelve equivalent Ni(3)Pr5Ni7 cuboctahedra, edges with six equivalent Ni(1)Pr6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(3)Pr5Ni7 cuboctahedra. In the third Ni site, Ni(2) is bonded to four equivalent Pr(2), two equivalent Ni(4), two equivalent Ni(5), and four equivalent Ni(2) atoms to form NiPr4Ni8 cuboctahedra that share corners with four equivalent Ni(2)Pr4Ni8 cuboctahedra, corners with twelve equivalent Ni(3)Pr5Ni7 cuboctahedra, edges with two equivalent Ni(2)Pr4Ni8 cuboctahedra, edges with eight equivalent Ni(3)Pr5Ni7 cuboctahedra, faces with two equivalent Ni(3)Pr5Ni7 cuboctahedra, and faces with eight equivalent Ni(2)Pr4Ni8 cuboctahedra. In the fourth Ni site, Ni(3) is bonded to two equivalent Pr(2), three equivalent Pr(1), one Ni(1), one Ni(4), one Ni(5), and four equivalent Ni(3) atoms to form distorted NiPr5Ni7 cuboctahedra that share corners with two equivalent Ni(1)Pr6Ni6 cuboctahedra, corners with six equivalent Ni(2)Pr4Ni8 cuboctahedra, corners with nine equivalent Ni(3)Pr5Ni7 cuboctahedra, edges with four equivalent Ni(2)Pr4Ni8 cuboctahedra, edges with four equivalent Ni(3)Pr5Ni7 cuboctahedra,  a faceface with one Ni(2)Pr4Ni8 cuboctahedra, faces with three equivalent Ni(1)Pr6Ni6 cuboctahedra, and faces with ten equivalent Ni(3)Pr5Ni7 cuboctahedra. In the fifth Ni site, Ni(4) is bonded in a 9-coordinate geometry to three equivalent Pr(2), three equivalent Ni(2), and three equivalent Ni(3) atoms. is represented by the CIF card [CIF]
data_Pr2Ni7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.066
_cell_length_b   5.066
_cell_length_c   24.670
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   548.331
_cell_formula_units_Z   4
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  0.333  0.667  0.470  1.0
  Pr  Pr1  1  0.667  0.333  0.530  1.0
  Pr  Pr2  1  0.667  0.333  0.970  1.0
  Pr  Pr3  1  0.333  0.667  0.030  1.0
  Pr  Pr4  1  0.333  0.667  0.326  1.0
  Pr  Pr5  1  0.667  0.333  0.674  1.0
  Pr  Pr6  1  0.667  0.333  0.826  1.0
  Pr  Pr7  1  0.333  0.667  0.174  1.0
  Ni  Ni8  1  0.000  0.000  0.500  1.0
  Ni  Ni9  1  0.000  0.000  0.000  1.0
  Ni  Ni10  1  0.833  0.167  0.250  1.0
  Ni  Ni11  1  0.833  0.666  0.250  1.0
  Ni  Ni12  1  0.334  0.167  0.250  1.0
  Ni  Ni13  1  0.167  0.833  0.750  1.0
  Ni  Ni14  1  0.167  0.334  0.750  1.0
  Ni  Ni15  1  0.666  0.833  0.750  1.0
  Ni  Ni16  1  0.834  0.166  0.412  1.0
  Ni  Ni17  1  0.834  0.668  0.412  1.0
  Ni  Ni18  1  0.332  0.166  0.412  1.0
  Ni  Ni19  1  0.166  0.834  0.588  1.0
  Ni  Ni20  1  0.166  0.332  0.588  1.0
  Ni  Ni21  1  0.668  0.834  0.588  1.0
  Ni  Ni22  1  0.166  0.834  0.912  1.0
  Ni  Ni23  1  0.166  0.332  0.912  1.0
  Ni  Ni24  1  0.668  0.834  0.912  1.0
  Ni  Ni25  1  0.834  0.166  0.088  1.0
  Ni  Ni26  1  0.834  0.668  0.088  1.0
  Ni  Ni27  1  0.332  0.166  0.088  1.0
  Ni  Ni28  1  0.000  0.000  0.331  1.0
  Ni  Ni29  1  0.000  0.000  0.669  1.0
  Ni  Ni30  1  0.000  0.000  0.831  1.0
  Ni  Ni31  1  0.000  0.000  0.169  1.0
  Ni  Ni32  1  0.333  0.667  0.668  1.0
  Ni  Ni33  1  0.667  0.333  0.332  1.0
  Ni  Ni34  1  0.667  0.333  0.168  1.0
  Ni  Ni35  1  0.333  0.667  0.832  1.0
[/CIF]
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