The material described by Ba8CaU4Y2O24 crystallizes in the tetragonal I4/mmm space group. Ba(1) is bonded to one O(1), one O(2), two equivalent O(3), two equivalent O(4), two equivalent O(5), and four equivalent O(6) atoms to form BaO12 cuboctahedra that share corners with twelve equivalent Ba(1)O12 cuboctahedra, faces with six equivalent Ba(1)O12 cuboctahedra,  a faceface with one Ca(1)O6 octahedra, faces with two equivalent U(1)O6 octahedra, faces with two equivalent U(2)O6 octahedra, and faces with two equivalent Y(1)O6 octahedra. Ca(1) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form CaO6 octahedra that share corners with two equivalent U(1)O6 octahedra, corners with four equivalent U(2)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. There are two inequivalent U sites. In the first U site, U(1) is bonded to one O(1), one O(2), and four equivalent O(6) atoms to form UO6 octahedra that share  a cornercorner with one Ca(1)O6 octahedra, corners with four equivalent Y(1)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second U site, U(2) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form UO6 octahedra that share corners with two equivalent Ca(1)O6 octahedra, corners with two equivalent Y(1)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. Y(1) is bonded to two equivalent O(5) and four equivalent O(6) atoms to form YO6 octahedra that share corners with two equivalent U(2)O6 octahedra, corners with four equivalent U(1)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-2°. There are six inequivalent O sites. In the first O site, O(2) is bonded in a distorted linear geometry to four equivalent Ba(1), one Ca(1), and one U(1) atom. In the second O site, O(3) is bonded in a distorted single-bond geometry to four equivalent Ba(1) and one U(2) atom. In the third O site, O(4) is bonded in a distorted linear geometry to four equivalent Ba(1), one Ca(1), and one U(2) atom. In the fourth O site, O(5) is bonded in a distorted linear geometry to four equivalent Ba(1), one U(2), and one Y(1) atom. In the fifth O site, O(6) is bonded in a distorted linear geometry to four equivalent Ba(1), one U(1), and one Y(1) atom. In the sixth O site, O(1) is bonded in a distorted single-bond geometry to four equivalent Ba(1) and one U(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba8CaY2U4O24
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.782
_cell_length_b   10.782
_cell_length_c   10.782
_cell_angle_alpha   132.007
_cell_angle_beta   132.007
_cell_angle_gamma   70.217
_symmetry_Int_Tables_number   1
_cell_volume   678.252
_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
  Ba  Ba0  1  0.879  0.357  0.000  1.0
  Ba  Ba1  1  0.357  0.879  0.000  1.0
  Ba  Ba2  1  0.121  0.643  0.000  1.0
  Ba  Ba3  1  0.643  0.121  0.000  1.0
  Ba  Ba4  1  0.357  0.357  0.478  1.0
  Ba  Ba5  1  0.879  0.879  0.522  1.0
  Ba  Ba6  1  0.121  0.121  0.478  1.0
  Ba  Ba7  1  0.643  0.643  0.522  1.0
  Ca  Ca8  1  0.500  0.500  0.000  1.0
  Y  Y9  1  0.250  0.750  0.500  1.0
  Y  Y10  1  0.750  0.250  0.500  1.0
  U  U11  1  0.253  0.253  0.000  1.0
  U  U12  1  0.747  0.747  0.000  1.0
  U  U13  1  0.500  0.000  0.500  1.0
  U  U14  1  0.000  0.500  0.500  1.0
  O  O15  1  0.139  0.139  0.000  1.0
  O  O16  1  0.861  0.861  0.000  1.0
  O  O17  1  0.368  0.368  0.000  1.0
  O  O18  1  0.632  0.632  0.000  1.0
  O  O19  1  0.000  0.271  0.271  1.0
  O  O20  1  0.000  0.729  0.729  1.0
  O  O21  1  0.271  0.000  0.271  1.0
  O  O22  1  0.729  0.000  0.729  1.0
  O  O23  1  0.500  0.761  0.261  1.0
  O  O24  1  0.500  0.239  0.739  1.0
  O  O25  1  0.761  0.500  0.261  1.0
  O  O26  1  0.239  0.500  0.739  1.0
  O  O27  1  0.123  0.623  0.500  1.0
  O  O28  1  0.377  0.877  0.500  1.0
  O  O29  1  0.877  0.377  0.500  1.0
  O  O30  1  0.623  0.123  0.500  1.0
  O  O31  1  0.249  0.492  0.243  1.0
  O  O32  1  0.249  0.006  0.757  1.0
  O  O33  1  0.994  0.751  0.243  1.0
  O  O34  1  0.508  0.751  0.757  1.0
  O  O35  1  0.751  0.508  0.757  1.0
  O  O36  1  0.751  0.994  0.243  1.0
  O  O37  1  0.006  0.249  0.757  1.0
  O  O38  1  0.492  0.249  0.243  1.0
[/CIF]
.
The material described by Ba8CaU4Y2O24 crystallizes in the tetragonal I4/mmm space group. Ba(1) is bonded to one O(1), one O(2), two equivalent O(3), two equivalent O(4), two equivalent O(5), and four equivalent O(6) atoms to form BaO12 cuboctahedra that share corners with twelve equivalent Ba(1)O12 cuboctahedra, faces with six equivalent Ba(1)O12 cuboctahedra,  a faceface with one Ca(1)O6 octahedra, faces with two equivalent U(1)O6 octahedra, faces with two equivalent U(2)O6 octahedra, and faces with two equivalent Y(1)O6 octahedra. Ca(1) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form CaO6 octahedra that share corners with two equivalent U(1)O6 octahedra, corners with four equivalent U(2)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. There are two inequivalent U sites. In the first U site, U(1) is bonded to one O(1), one O(2), and four equivalent O(6) atoms to form UO6 octahedra that share  a cornercorner with one Ca(1)O6 octahedra, corners with four equivalent Y(1)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second U site, U(2) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form UO6 octahedra that share corners with two equivalent Ca(1)O6 octahedra, corners with two equivalent Y(1)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedra are not tilted. Y(1) is bonded to two equivalent O(5) and four equivalent O(6) atoms to form YO6 octahedra that share corners with two equivalent U(2)O6 octahedra, corners with four equivalent U(1)O6 octahedra, and faces with eight equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-2°. There are six inequivalent O sites. In the first O site, O(2) is bonded in a distorted linear geometry to four equivalent Ba(1), one Ca(1), and one U(1) atom. In the second O site, O(3) is bonded in a distorted single-bond geometry to four equivalent Ba(1) and one U(2) atom. In the third O site, O(4) is bonded in a distorted linear geometry to four equivalent Ba(1), one Ca(1), and one U(2) atom. In the fourth O site, O(5) is bonded in a distorted linear geometry to four equivalent Ba(1), one U(2), and one Y(1) atom. In the fifth O site, O(6) is bonded in a distorted linear geometry to four equivalent Ba(1), one U(1), and one Y(1) atom. In the sixth O site, O(1) is bonded in a distorted single-bond geometry to four equivalent Ba(1) and one U(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba8CaY2U4O24
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.782
_cell_length_b   10.782
_cell_length_c   10.782
_cell_angle_alpha   132.007
_cell_angle_beta   132.007
_cell_angle_gamma   70.217
_symmetry_Int_Tables_number   1
_cell_volume   678.252
_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
  Ba  Ba0  1  0.879  0.357  0.000  1.0
  Ba  Ba1  1  0.357  0.879  0.000  1.0
  Ba  Ba2  1  0.121  0.643  0.000  1.0
  Ba  Ba3  1  0.643  0.121  0.000  1.0
  Ba  Ba4  1  0.357  0.357  0.478  1.0
  Ba  Ba5  1  0.879  0.879  0.522  1.0
  Ba  Ba6  1  0.121  0.121  0.478  1.0
  Ba  Ba7  1  0.643  0.643  0.522  1.0
  Ca  Ca8  1  0.500  0.500  0.000  1.0
  Y  Y9  1  0.250  0.750  0.500  1.0
  Y  Y10  1  0.750  0.250  0.500  1.0
  U  U11  1  0.253  0.253  0.000  1.0
  U  U12  1  0.747  0.747  0.000  1.0
  U  U13  1  0.500  0.000  0.500  1.0
  U  U14  1  0.000  0.500  0.500  1.0
  O  O15  1  0.139  0.139  0.000  1.0
  O  O16  1  0.861  0.861  0.000  1.0
  O  O17  1  0.368  0.368  0.000  1.0
  O  O18  1  0.632  0.632  0.000  1.0
  O  O19  1  0.000  0.271  0.271  1.0
  O  O20  1  0.000  0.729  0.729  1.0
  O  O21  1  0.271  0.000  0.271  1.0
  O  O22  1  0.729  0.000  0.729  1.0
  O  O23  1  0.500  0.761  0.261  1.0
  O  O24  1  0.500  0.239  0.739  1.0
  O  O25  1  0.761  0.500  0.261  1.0
  O  O26  1  0.239  0.500  0.739  1.0
  O  O27  1  0.123  0.623  0.500  1.0
  O  O28  1  0.377  0.877  0.500  1.0
  O  O29  1  0.877  0.377  0.500  1.0
  O  O30  1  0.623  0.123  0.500  1.0
  O  O31  1  0.249  0.492  0.243  1.0
  O  O32  1  0.249  0.006  0.757  1.0
  O  O33  1  0.994  0.751  0.243  1.0
  O  O34  1  0.508  0.751  0.757  1.0
  O  O35  1  0.751  0.508  0.757  1.0
  O  O36  1  0.751  0.994  0.243  1.0
  O  O37  1  0.006  0.249  0.757  1.0
  O  O38  1  0.492  0.249  0.243  1.0
[/CIF]
.