The material described by U4Ni5Al18 crystallizes in the monoclinic Cm space group. There are four inequivalent U sites. In the first U site, U(1) is bonded in a 15-coordinate geometry to two equivalent Ni(1), one Al(11), one Al(12), one Al(15), one Al(5), one Al(7), two equivalent Al(10), two equivalent Al(17), two equivalent Al(2), and two equivalent Al(6) atoms. In the second U site, U(2) is bonded in a 15-coordinate geometry to two equivalent Ni(2), one Al(1), one Al(15), one Al(18), one Al(4), one Al(8), two equivalent Al(13), two equivalent Al(14), two equivalent Al(3), and two equivalent Al(9) atoms. In the third U site, U(3) is bonded in a 15-coordinate geometry to two equivalent Ni(5), one Al(1), one Al(13), one Al(17), one Al(4), one Al(7), two equivalent Al(11), two equivalent Al(16), two equivalent Al(3), and two equivalent Al(8) atoms. In the fourth U site, U(4) is bonded in a 15-coordinate geometry to two equivalent Ni(3), one Al(1), one Al(15), one Al(5), one Al(6), one Al(9), two equivalent Al(12), two equivalent Al(14), two equivalent Al(18), and two equivalent Al(2) atoms. There are five inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 7-coordinate geometry to two equivalent U(1), one Al(10), one Al(17), one Al(4), two equivalent Al(11), and two equivalent Al(7) atoms. In the second Ni site, Ni(2) is bonded in a 7-coordinate geometry to two equivalent U(2), one Al(1), one Al(13), one Al(9), two equivalent Al(18), and two equivalent Al(8) atoms. In the third Ni site, Ni(3) is bonded in a 7-coordinate geometry to two equivalent U(4), one Al(12), one Al(15), one Al(18), two equivalent Al(6), and two equivalent Al(9) atoms. In the fourth Ni site, Ni(4) is bonded in a 9-coordinate geometry to one Al(12), one Al(17), one Al(7), two equivalent Al(10), two equivalent Al(16), and two equivalent Al(5) atoms. In the fifth Ni site, Ni(5) is bonded in a 7-coordinate geometry to two equivalent U(3), one Al(16), one Al(4), one Al(8), two equivalent Al(13), and two equivalent Al(7) atoms. There are eighteen inequivalent Al sites. In the first Al site, Al(1) is bonded in a distorted single-bond geometry to one U(2), one U(3), one U(4), one Ni(2), two equivalent Al(14), and two equivalent Al(3) atoms. In the second Al site, Al(2) is bonded in a 11-coordinate geometry to two equivalent U(1), two equivalent U(4), one Al(12), one Al(17), one Al(6), two equivalent Al(15), and two equivalent Al(5) atoms. In the third Al site, Al(3) is bonded in a 12-coordinate geometry to two equivalent U(2), two equivalent U(3), one Al(11), one Al(13), one Al(14), one Al(8), two equivalent Al(1), and two equivalent Al(4) atoms. In the fourth Al site, Al(4) is bonded in a 2-coordinate geometry to one U(2), one U(3), one Ni(1), one Ni(5), and two equivalent Al(3) atoms. In the fifth Al site, Al(5) is bonded to one U(1), one U(4), two equivalent Ni(4), one Al(10), one Al(16), two equivalent Al(12), two equivalent Al(17), and two equivalent Al(2) atoms to form distorted face-sharing AlU2Al8Ni2 cuboctahedra. In the sixth Al site, Al(6) is bonded in a 2-coordinate geometry to one U(4), two equivalent U(1), two equivalent Ni(3), and one Al(2) atom. In the seventh Al site, Al(7) is bonded in a 5-coordinate geometry to one U(1), one U(3), one Ni(4), two equivalent Ni(1), and two equivalent Ni(5) atoms. In the eighth Al site, Al(8) is bonded in a 3-coordinate geometry to one U(2), two equivalent U(3), one Ni(5), two equivalent Ni(2), and one Al(3) atom. In the ninth Al site, Al(9) is bonded in a 3-coordinate geometry to one U(4), two equivalent U(2), one Ni(2), two equivalent Ni(3), and one Al(14) atom. In the tenth Al site, Al(10) is bonded in a 3-coordinate geometry to two equivalent U(1), one Ni(1), two equivalent Ni(4), and one Al(5) atom. In the eleventh Al site, Al(11) is bonded in a distorted water-like geometry to one U(1), two equivalent U(3), two equivalent Ni(1), and one Al(3) atom. In the twelfth Al site, Al(12) is bonded in a distorted bent 150 degrees geometry to one U(1), two equivalent U(4), one Ni(3), one Ni(4), one Al(2), and two equivalent Al(5) atoms. In the thirteenth Al site, Al(13) is bonded in a distorted trigonal non-coplanar geometry to one U(3), two equivalent U(2), one Ni(2), two equivalent Ni(5), and one Al(3) atom. In the fourteenth Al site, Al(14) is bonded in a 10-coordinate geometry to two equivalent U(2), two equivalent U(4), one Al(18), one Al(3), one Al(9), two equivalent Al(1), and two equivalent Al(15) atoms. In the fifteenth Al site, Al(15) is bonded in a distorted single-bond geometry to one U(1), one U(2), one U(4), one Ni(3), two equivalent Al(14), and two equivalent Al(2) atoms. In the sixteenth Al site, Al(16) is bonded in a 3-coordinate geometry to two equivalent U(3), one Ni(5), two equivalent Ni(4), and one Al(5) atom. In the seventeenth Al site, Al(17) is bonded in a distorted bent 150 degrees geometry to one U(3), two equivalent U(1), one Ni(1), one Ni(4), one Al(2), and two equivalent Al(5) atoms. In the eighteenth Al site, Al(18) is bonded in a 3-coordinate geometry to one U(2), two equivalent U(4), one Ni(3), two equivalent Ni(2), and one Al(14) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_U4Al18Ni5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.067
_cell_length_b   8.067
_cell_length_c   16.063
_cell_angle_alpha   63.673
_cell_angle_beta   63.673
_cell_angle_gamma   28.982
_symmetry_Int_Tables_number   1
_cell_volume   450.228
_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
  U  U0  1  0.768  0.768  0.661  1.0
  U  U1  1  0.562  0.562  0.109  1.0
  U  U2  1  0.232  0.232  0.336  1.0
  U  U3  1  0.443  0.443  0.888  1.0
  Al  Al4  1  0.370  0.370  0.110  1.0
  Al  Al5  1  0.105  0.105  0.775  1.0
  Al  Al6  1  0.897  0.897  0.220  1.0
  Al  Al7  1  0.431  0.431  0.321  1.0
  Al  Al8  1  0.565  0.565  0.667  1.0
  Al  Al9  1  0.295  0.295  0.787  1.0
  Al  Al10  1  0.977  0.977  0.453  1.0
  Al  Al11  1  0.713  0.713  0.205  1.0
  Al  Al12  1  0.205  0.205  0.972  1.0
  Al  Al13  1  0.427  0.427  0.600  1.0
  Al  Al14  1  0.802  0.802  0.439  1.0
  Al  Al15  1  0.936  0.936  0.740  1.0
  Al  Al16  1  0.072  0.072  0.257  1.0
  Al  Al17  1  0.003  0.003  0.997  1.0
  Al  Al18  1  0.635  0.635  0.883  1.0
  Al  Al19  1  0.611  0.611  0.479  1.0
  Al  Al20  1  0.187  0.187  0.565  1.0
  Al  Al21  1  0.800  0.800  0.021  1.0
  Ni  Ni22  1  0.359  0.359  0.487  1.0
  Ni  Ni23  1  0.219  0.219  0.114  1.0
  Ni  Ni24  1  0.787  0.787  0.877  1.0
  Ni  Ni25  1  0.030  0.030  0.573  1.0
  Ni  Ni26  1  0.566  0.566  0.350  1.0
[/CIF]
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The material described by U4Ni5Al18 crystallizes in the monoclinic Cm space group. There are four inequivalent U sites. In the first U site, U(1) is bonded in a 15-coordinate geometry to two equivalent Ni(1), one Al(11), one Al(12), one Al(15), one Al(5), one Al(7), two equivalent Al(10), two equivalent Al(17), two equivalent Al(2), and two equivalent Al(6) atoms. In the second U site, U(2) is bonded in a 15-coordinate geometry to two equivalent Ni(2), one Al(1), one Al(15), one Al(18), one Al(4), one Al(8), two equivalent Al(13), two equivalent Al(14), two equivalent Al(3), and two equivalent Al(9) atoms. In the third U site, U(3) is bonded in a 15-coordinate geometry to two equivalent Ni(5), one Al(1), one Al(13), one Al(17), one Al(4), one Al(7), two equivalent Al(11), two equivalent Al(16), two equivalent Al(3), and two equivalent Al(8) atoms. In the fourth U site, U(4) is bonded in a 15-coordinate geometry to two equivalent Ni(3), one Al(1), one Al(15), one Al(5), one Al(6), one Al(9), two equivalent Al(12), two equivalent Al(14), two equivalent Al(18), and two equivalent Al(2) atoms. There are five inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 7-coordinate geometry to two equivalent U(1), one Al(10), one Al(17), one Al(4), two equivalent Al(11), and two equivalent Al(7) atoms. In the second Ni site, Ni(2) is bonded in a 7-coordinate geometry to two equivalent U(2), one Al(1), one Al(13), one Al(9), two equivalent Al(18), and two equivalent Al(8) atoms. In the third Ni site, Ni(3) is bonded in a 7-coordinate geometry to two equivalent U(4), one Al(12), one Al(15), one Al(18), two equivalent Al(6), and two equivalent Al(9) atoms. In the fourth Ni site, Ni(4) is bonded in a 9-coordinate geometry to one Al(12), one Al(17), one Al(7), two equivalent Al(10), two equivalent Al(16), and two equivalent Al(5) atoms. In the fifth Ni site, Ni(5) is bonded in a 7-coordinate geometry to two equivalent U(3), one Al(16), one Al(4), one Al(8), two equivalent Al(13), and two equivalent Al(7) atoms. There are eighteen inequivalent Al sites. In the first Al site, Al(1) is bonded in a distorted single-bond geometry to one U(2), one U(3), one U(4), one Ni(2), two equivalent Al(14), and two equivalent Al(3) atoms. In the second Al site, Al(2) is bonded in a 11-coordinate geometry to two equivalent U(1), two equivalent U(4), one Al(12), one Al(17), one Al(6), two equivalent Al(15), and two equivalent Al(5) atoms. In the third Al site, Al(3) is bonded in a 12-coordinate geometry to two equivalent U(2), two equivalent U(3), one Al(11), one Al(13), one Al(14), one Al(8), two equivalent Al(1), and two equivalent Al(4) atoms. In the fourth Al site, Al(4) is bonded in a 2-coordinate geometry to one U(2), one U(3), one Ni(1), one Ni(5), and two equivalent Al(3) atoms. In the fifth Al site, Al(5) is bonded to one U(1), one U(4), two equivalent Ni(4), one Al(10), one Al(16), two equivalent Al(12), two equivalent Al(17), and two equivalent Al(2) atoms to form distorted face-sharing AlU2Al8Ni2 cuboctahedra. In the sixth Al site, Al(6) is bonded in a 2-coordinate geometry to one U(4), two equivalent U(1), two equivalent Ni(3), and one Al(2) atom. In the seventh Al site, Al(7) is bonded in a 5-coordinate geometry to one U(1), one U(3), one Ni(4), two equivalent Ni(1), and two equivalent Ni(5) atoms. In the eighth Al site, Al(8) is bonded in a 3-coordinate geometry to one U(2), two equivalent U(3), one Ni(5), two equivalent Ni(2), and one Al(3) atom. In the ninth Al site, Al(9) is bonded in a 3-coordinate geometry to one U(4), two equivalent U(2), one Ni(2), two equivalent Ni(3), and one Al(14) atom. In the tenth Al site, Al(10) is bonded in a 3-coordinate geometry to two equivalent U(1), one Ni(1), two equivalent Ni(4), and one Al(5) atom. In the eleventh Al site, Al(11) is bonded in a distorted water-like geometry to one U(1), two equivalent U(3), two equivalent Ni(1), and one Al(3) atom. In the twelfth Al site, Al(12) is bonded in a distorted bent 150 degrees geometry to one U(1), two equivalent U(4), one Ni(3), one Ni(4), one Al(2), and two equivalent Al(5) atoms. In the thirteenth Al site, Al(13) is bonded in a distorted trigonal non-coplanar geometry to one U(3), two equivalent U(2), one Ni(2), two equivalent Ni(5), and one Al(3) atom. In the fourteenth Al site, Al(14) is bonded in a 10-coordinate geometry to two equivalent U(2), two equivalent U(4), one Al(18), one Al(3), one Al(9), two equivalent Al(1), and two equivalent Al(15) atoms. In the fifteenth Al site, Al(15) is bonded in a distorted single-bond geometry to one U(1), one U(2), one U(4), one Ni(3), two equivalent Al(14), and two equivalent Al(2) atoms. In the sixteenth Al site, Al(16) is bonded in a 3-coordinate geometry to two equivalent U(3), one Ni(5), two equivalent Ni(4), and one Al(5) atom. In the seventeenth Al site, Al(17) is bonded in a distorted bent 150 degrees geometry to one U(3), two equivalent U(1), one Ni(1), one Ni(4), one Al(2), and two equivalent Al(5) atoms. In the eighteenth Al site, Al(18) is bonded in a 3-coordinate geometry to one U(2), two equivalent U(4), one Ni(3), two equivalent Ni(2), and one Al(14) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_U4Al18Ni5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.067
_cell_length_b   8.067
_cell_length_c   16.063
_cell_angle_alpha   63.673
_cell_angle_beta   63.673
_cell_angle_gamma   28.982
_symmetry_Int_Tables_number   1
_cell_volume   450.228
_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
  U  U0  1  0.768  0.768  0.661  1.0
  U  U1  1  0.562  0.562  0.109  1.0
  U  U2  1  0.232  0.232  0.336  1.0
  U  U3  1  0.443  0.443  0.888  1.0
  Al  Al4  1  0.370  0.370  0.110  1.0
  Al  Al5  1  0.105  0.105  0.775  1.0
  Al  Al6  1  0.897  0.897  0.220  1.0
  Al  Al7  1  0.431  0.431  0.321  1.0
  Al  Al8  1  0.565  0.565  0.667  1.0
  Al  Al9  1  0.295  0.295  0.787  1.0
  Al  Al10  1  0.977  0.977  0.453  1.0
  Al  Al11  1  0.713  0.713  0.205  1.0
  Al  Al12  1  0.205  0.205  0.972  1.0
  Al  Al13  1  0.427  0.427  0.600  1.0
  Al  Al14  1  0.802  0.802  0.439  1.0
  Al  Al15  1  0.936  0.936  0.740  1.0
  Al  Al16  1  0.072  0.072  0.257  1.0
  Al  Al17  1  0.003  0.003  0.997  1.0
  Al  Al18  1  0.635  0.635  0.883  1.0
  Al  Al19  1  0.611  0.611  0.479  1.0
  Al  Al20  1  0.187  0.187  0.565  1.0
  Al  Al21  1  0.800  0.800  0.021  1.0
  Ni  Ni22  1  0.359  0.359  0.487  1.0
  Ni  Ni23  1  0.219  0.219  0.114  1.0
  Ni  Ni24  1  0.787  0.787  0.877  1.0
  Ni  Ni25  1  0.030  0.030  0.573  1.0
  Ni  Ni26  1  0.566  0.566  0.350  1.0
[/CIF]
.