The compound described by Zr8Ni21 crystallizes in the triclinic P-1 space group. There are four inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a 13-coordinate geometry to one Ni(1), one Ni(11), one Ni(2), one Ni(4), one Ni(5), one Ni(6), one Ni(8), two equivalent Ni(10), two equivalent Ni(3), and two equivalent Ni(9) atoms. In the second Zr site, Zr(2) is bonded in a 10-coordinate geometry to one Ni(2), one Ni(3), one Ni(4), one Ni(6), one Ni(8), one Ni(9), two equivalent Ni(5), and two equivalent Ni(7) atoms. In the third Zr site, Zr(3) is bonded in a 12-coordinate geometry to one Ni(10), one Ni(5), one Ni(7), one Ni(8), two equivalent Ni(11), two equivalent Ni(2), two equivalent Ni(4), and two equivalent Ni(6) atoms. In the fourth Zr site, Zr(4) is bonded in a 12-coordinate geometry to one Ni(1), one Ni(10), one Ni(11), one Ni(2), one Ni(5), one Ni(6), one Ni(7), one Ni(9), two equivalent Ni(3), and two equivalent Ni(8) atoms. There are eleven inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent Zr(1), two equivalent Zr(4), two equivalent Ni(10), two equivalent Ni(11), two equivalent Ni(2), and two equivalent Ni(6) atoms to form face-sharing NiZr4Ni8 cuboctahedra. In the second Ni site, Ni(2) is bonded to one Zr(1), one Zr(2), one Zr(4), two equivalent Zr(3), one Ni(1), one Ni(10), one Ni(11), one Ni(3), one Ni(4), one Ni(6), and one Ni(8) atom to form distorted NiZr5Ni7 cuboctahedra that share  a cornercorner with one Ni(2)Zr5Ni7 cuboctahedra,  an edgeedge with one Ni(2)Zr5Ni7 cuboctahedra,  a faceface with one Ni(1)Zr4Ni8 cuboctahedra, and faces with three equivalent Ni(6)Zr5Ni7 cuboctahedra. In the third Ni site, Ni(3) is bonded in a 5-coordinate geometry to one Zr(2), two equivalent Zr(1), two equivalent Zr(4), one Ni(2), one Ni(5), and two equivalent Ni(8) atoms. In the fourth Ni site, Ni(4) is bonded in a 10-coordinate geometry to one Zr(1), one Zr(2), two equivalent Zr(3), one Ni(11), one Ni(2), one Ni(5), one Ni(7), one Ni(8), and one Ni(9) atom. In the fifth Ni site, Ni(5) is bonded in a 12-coordinate geometry to one Zr(1), one Zr(3), one Zr(4), two equivalent Zr(2), one Ni(10), one Ni(11), one Ni(3), one Ni(4), one Ni(6), one Ni(7), and one Ni(9) atom. In the sixth Ni site, Ni(6) is bonded to one Zr(1), one Zr(2), one Zr(4), two equivalent Zr(3), one Ni(1), one Ni(10), one Ni(11), one Ni(2), one Ni(5), one Ni(7), and one Ni(9) atom to form distorted NiZr5Ni7 cuboctahedra that share  a cornercorner with one Ni(6)Zr5Ni7 cuboctahedra,  an edgeedge with one Ni(6)Zr5Ni7 cuboctahedra,  a faceface with one Ni(1)Zr4Ni8 cuboctahedra, and faces with three equivalent Ni(2)Zr5Ni7 cuboctahedra. In the seventh Ni site, Ni(7) is bonded in a 12-coordinate geometry to one Zr(3), one Zr(4), two equivalent Zr(2), one Ni(11), one Ni(4), one Ni(5), one Ni(6), one Ni(7), one Ni(8), and two equivalent Ni(9) atoms. In the eighth Ni site, Ni(8) is bonded in a 12-coordinate geometry to one Zr(1), one Zr(2), one Zr(3), two equivalent Zr(4), one Ni(10), one Ni(2), one Ni(4), one Ni(7), one Ni(9), and two equivalent Ni(3) atoms. In the ninth Ni site, Ni(9) is bonded in a 3-coordinate geometry to one Zr(2), one Zr(4), two equivalent Zr(1), one Ni(4), one Ni(5), one Ni(6), one Ni(8), and two equivalent Ni(7) atoms. In the tenth Ni site, Ni(10) is bonded in a 12-coordinate geometry to one Zr(3), one Zr(4), two equivalent Zr(1), one Ni(1), one Ni(10), one Ni(2), one Ni(5), one Ni(6), one Ni(8), and two equivalent Ni(11) atoms. In the eleventh Ni site, Ni(11) is bonded in a 4-coordinate geometry to one Zr(1), one Zr(4), two equivalent Zr(3), one Ni(1), one Ni(2), one Ni(4), one Ni(5), one Ni(6), one Ni(7), and two equivalent Ni(10) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Zr8Ni21
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.451
_cell_length_b   8.082
_cell_length_c   8.567
_cell_angle_alpha   75.350
_cell_angle_beta   68.026
_cell_angle_gamma   75.325
_symmetry_Int_Tables_number   1
_cell_volume   394.426
_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
  Zr  Zr0  1  0.433  0.962  0.753  1.0
  Zr  Zr1  1  0.567  0.038  0.247  1.0
  Zr  Zr2  1  0.753  0.440  0.393  1.0
  Zr  Zr3  1  0.247  0.560  0.607  1.0
  Zr  Zr4  1  0.752  0.563  0.966  1.0
  Zr  Zr5  1  0.248  0.437  0.034  1.0
  Zr  Zr6  1  0.931  0.096  0.686  1.0
  Zr  Zr7  1  0.069  0.904  0.314  1.0
  Ni  Ni8  1  0.000  0.000  0.000  1.0
  Ni  Ni9  1  0.098  0.759  0.848  1.0
  Ni  Ni10  1  0.902  0.241  0.152  1.0
  Ni  Ni11  1  0.287  0.885  0.530  1.0
  Ni  Ni12  1  0.713  0.115  0.470  1.0
  Ni  Ni13  1  0.515  0.617  0.756  1.0
  Ni  Ni14  1  0.485  0.383  0.244  1.0
  Ni  Ni15  1  0.515  0.292  0.726  1.0
  Ni  Ni16  1  0.099  0.280  0.846  1.0
  Ni  Ni17  1  0.901  0.720  0.154  1.0
  Ni  Ni18  1  0.119  0.555  0.349  1.0
  Ni  Ni19  1  0.881  0.445  0.651  1.0
  Ni  Ni20  1  0.136  0.213  0.342  1.0
  Ni  Ni21  1  0.864  0.787  0.658  1.0
  Ni  Ni22  1  0.303  0.245  0.541  1.0
  Ni  Ni23  1  0.697  0.755  0.459  1.0
  Ni  Ni24  1  0.316  0.099  0.036  1.0
  Ni  Ni25  1  0.684  0.901  0.964  1.0
  Ni  Ni26  1  0.318  0.744  0.048  1.0
  Ni  Ni27  1  0.682  0.256  0.952  1.0
  Ni  Ni28  1  0.485  0.708  0.274  1.0
[/CIF]
.
The compound described by Zr8Ni21 crystallizes in the triclinic P-1 space group. There are four inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a 13-coordinate geometry to one Ni(1), one Ni(11), one Ni(2), one Ni(4), one Ni(5), one Ni(6), one Ni(8), two equivalent Ni(10), two equivalent Ni(3), and two equivalent Ni(9) atoms. In the second Zr site, Zr(2) is bonded in a 10-coordinate geometry to one Ni(2), one Ni(3), one Ni(4), one Ni(6), one Ni(8), one Ni(9), two equivalent Ni(5), and two equivalent Ni(7) atoms. In the third Zr site, Zr(3) is bonded in a 12-coordinate geometry to one Ni(10), one Ni(5), one Ni(7), one Ni(8), two equivalent Ni(11), two equivalent Ni(2), two equivalent Ni(4), and two equivalent Ni(6) atoms. In the fourth Zr site, Zr(4) is bonded in a 12-coordinate geometry to one Ni(1), one Ni(10), one Ni(11), one Ni(2), one Ni(5), one Ni(6), one Ni(7), one Ni(9), two equivalent Ni(3), and two equivalent Ni(8) atoms. There are eleven inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent Zr(1), two equivalent Zr(4), two equivalent Ni(10), two equivalent Ni(11), two equivalent Ni(2), and two equivalent Ni(6) atoms to form face-sharing NiZr4Ni8 cuboctahedra. In the second Ni site, Ni(2) is bonded to one Zr(1), one Zr(2), one Zr(4), two equivalent Zr(3), one Ni(1), one Ni(10), one Ni(11), one Ni(3), one Ni(4), one Ni(6), and one Ni(8) atom to form distorted NiZr5Ni7 cuboctahedra that share  a cornercorner with one Ni(2)Zr5Ni7 cuboctahedra,  an edgeedge with one Ni(2)Zr5Ni7 cuboctahedra,  a faceface with one Ni(1)Zr4Ni8 cuboctahedra, and faces with three equivalent Ni(6)Zr5Ni7 cuboctahedra. In the third Ni site, Ni(3) is bonded in a 5-coordinate geometry to one Zr(2), two equivalent Zr(1), two equivalent Zr(4), one Ni(2), one Ni(5), and two equivalent Ni(8) atoms. In the fourth Ni site, Ni(4) is bonded in a 10-coordinate geometry to one Zr(1), one Zr(2), two equivalent Zr(3), one Ni(11), one Ni(2), one Ni(5), one Ni(7), one Ni(8), and one Ni(9) atom. In the fifth Ni site, Ni(5) is bonded in a 12-coordinate geometry to one Zr(1), one Zr(3), one Zr(4), two equivalent Zr(2), one Ni(10), one Ni(11), one Ni(3), one Ni(4), one Ni(6), one Ni(7), and one Ni(9) atom. In the sixth Ni site, Ni(6) is bonded to one Zr(1), one Zr(2), one Zr(4), two equivalent Zr(3), one Ni(1), one Ni(10), one Ni(11), one Ni(2), one Ni(5), one Ni(7), and one Ni(9) atom to form distorted NiZr5Ni7 cuboctahedra that share  a cornercorner with one Ni(6)Zr5Ni7 cuboctahedra,  an edgeedge with one Ni(6)Zr5Ni7 cuboctahedra,  a faceface with one Ni(1)Zr4Ni8 cuboctahedra, and faces with three equivalent Ni(2)Zr5Ni7 cuboctahedra. In the seventh Ni site, Ni(7) is bonded in a 12-coordinate geometry to one Zr(3), one Zr(4), two equivalent Zr(2), one Ni(11), one Ni(4), one Ni(5), one Ni(6), one Ni(7), one Ni(8), and two equivalent Ni(9) atoms. In the eighth Ni site, Ni(8) is bonded in a 12-coordinate geometry to one Zr(1), one Zr(2), one Zr(3), two equivalent Zr(4), one Ni(10), one Ni(2), one Ni(4), one Ni(7), one Ni(9), and two equivalent Ni(3) atoms. In the ninth Ni site, Ni(9) is bonded in a 3-coordinate geometry to one Zr(2), one Zr(4), two equivalent Zr(1), one Ni(4), one Ni(5), one Ni(6), one Ni(8), and two equivalent Ni(7) atoms. In the tenth Ni site, Ni(10) is bonded in a 12-coordinate geometry to one Zr(3), one Zr(4), two equivalent Zr(1), one Ni(1), one Ni(10), one Ni(2), one Ni(5), one Ni(6), one Ni(8), and two equivalent Ni(11) atoms. In the eleventh Ni site, Ni(11) is bonded in a 4-coordinate geometry to one Zr(1), one Zr(4), two equivalent Zr(3), one Ni(1), one Ni(2), one Ni(4), one Ni(5), one Ni(6), one Ni(7), and two equivalent Ni(10) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Zr8Ni21
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.451
_cell_length_b   8.082
_cell_length_c   8.567
_cell_angle_alpha   75.350
_cell_angle_beta   68.026
_cell_angle_gamma   75.325
_symmetry_Int_Tables_number   1
_cell_volume   394.426
_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
  Zr  Zr0  1  0.433  0.962  0.753  1.0
  Zr  Zr1  1  0.567  0.038  0.247  1.0
  Zr  Zr2  1  0.753  0.440  0.393  1.0
  Zr  Zr3  1  0.247  0.560  0.607  1.0
  Zr  Zr4  1  0.752  0.563  0.966  1.0
  Zr  Zr5  1  0.248  0.437  0.034  1.0
  Zr  Zr6  1  0.931  0.096  0.686  1.0
  Zr  Zr7  1  0.069  0.904  0.314  1.0
  Ni  Ni8  1  0.000  0.000  0.000  1.0
  Ni  Ni9  1  0.098  0.759  0.848  1.0
  Ni  Ni10  1  0.902  0.241  0.152  1.0
  Ni  Ni11  1  0.287  0.885  0.530  1.0
  Ni  Ni12  1  0.713  0.115  0.470  1.0
  Ni  Ni13  1  0.515  0.617  0.756  1.0
  Ni  Ni14  1  0.485  0.383  0.244  1.0
  Ni  Ni15  1  0.515  0.292  0.726  1.0
  Ni  Ni16  1  0.099  0.280  0.846  1.0
  Ni  Ni17  1  0.901  0.720  0.154  1.0
  Ni  Ni18  1  0.119  0.555  0.349  1.0
  Ni  Ni19  1  0.881  0.445  0.651  1.0
  Ni  Ni20  1  0.136  0.213  0.342  1.0
  Ni  Ni21  1  0.864  0.787  0.658  1.0
  Ni  Ni22  1  0.303  0.245  0.541  1.0
  Ni  Ni23  1  0.697  0.755  0.459  1.0
  Ni  Ni24  1  0.316  0.099  0.036  1.0
  Ni  Ni25  1  0.684  0.901  0.964  1.0
  Ni  Ni26  1  0.318  0.744  0.048  1.0
  Ni  Ni27  1  0.682  0.256  0.952  1.0
  Ni  Ni28  1  0.485  0.708  0.274  1.0
[/CIF]
.