The crystal structure described by CeAl8O16 crystallizes in the orthorhombic Pmm2 space group. Ce(1) is bonded to two equivalent O(14), two equivalent O(16), two equivalent O(7), two equivalent O(8), and four equivalent O(2) atoms to form CeO12 cuboctahedra that share corners with four equivalent Ce(1)O12 cuboctahedra, faces with four equivalent Ce(1)O12 cuboctahedra, faces with four equivalent Al(3)O6 octahedra, and faces with four equivalent Al(6)O6 octahedra. There are eight inequivalent Al sites. In the first Al site, Al(1) is bonded in a square co-planar geometry to one O(1), one O(6), and two equivalent O(12) atoms. In the second Al site, Al(2) is bonded in a linear geometry to one O(1) and one O(13) atom. In the third Al site, Al(3) is bonded to one O(13), one O(2), two equivalent O(14), and two equivalent O(7) atoms to form distorted AlO6 octahedra that share  a cornercorner with one Al(6)O6 octahedra, corners with four equivalent Al(3)O6 octahedra, and faces with four equivalent Ce(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-21°. In the fourth Al site, Al(4) is bonded in a linear geometry to one O(15) and one O(3) atom. In the fifth Al site, Al(5) is bonded in a square co-planar geometry to one O(3), one O(4), and two equivalent O(9) atoms. In the sixth Al site, Al(6) is bonded to one O(15), one O(2), two equivalent O(16), and two equivalent O(8) atoms to form distorted AlO6 octahedra that share  a cornercorner with one Al(3)O6 octahedra, corners with four equivalent Al(6)O6 octahedra, and faces with four equivalent Ce(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-21°. In the seventh Al site, Al(7) is bonded in a square co-planar geometry to one O(4), one O(5), and two equivalent O(10) atoms. In the eighth Al site, Al(8) is bonded in a square co-planar geometry to one O(5), one O(6), and two equivalent O(11) atoms. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one Al(1) and one Al(2) atom. In the second O site, O(2) is bonded to four equivalent Ce(1), one Al(3), and one Al(6) atom to form a mixture of edge and corner-sharing OCe4Al2 octahedra. The corner-sharing octahedra are not tilted. In the third O site, O(3) is bonded in a linear geometry to one Al(4) and one Al(5) atom. In the fourth O site, O(4) is bonded in a linear geometry to one Al(5) and one Al(7) atom. In the fifth O site, O(5) is bonded in a linear geometry to one Al(7) and one Al(8) atom. In the sixth O site, O(6) is bonded in a linear geometry to one Al(1) and one Al(8) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to two equivalent Ce(1) and two equivalent Al(3) atoms. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to two equivalent Ce(1) and two equivalent Al(6) atoms. In the ninth O site, O(9) is bonded in a linear geometry to two equivalent Al(5) atoms. In the tenth O site, O(10) is bonded in a linear geometry to two equivalent Al(7) atoms. In the eleventh O site, O(11) is bonded in a linear geometry to two equivalent Al(8) atoms. In the twelfth O site, O(12) is bonded in a linear geometry to two equivalent Al(1) atoms. In the thirteenth O site, O(13) is bonded in a linear geometry to one Al(2) and one Al(3) atom. In the fourteenth O site, O(14) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ce(1) and two equivalent Al(3) atoms. In the fifteenth O site, O(15) is bonded in a linear geometry to one Al(4) and one Al(6) atom. In the sixteenth O site, O(16) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ce(1) and two equivalent Al(6) atoms. is represented by the CIF file [CIF]
data_CeAl8O16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.590
_cell_length_b   3.676
_cell_length_c   28.494
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   376.075
_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
  Ce  Ce0  1  0.500  0.000  0.312  1.0
  Al  Al1  1  0.000  0.500  0.997  1.0
  Al  Al2  1  0.000  0.500  0.118  1.0
  Al  Al3  1  0.000  0.500  0.240  1.0
  Al  Al4  1  0.000  0.500  0.506  1.0
  Al  Al5  1  0.000  0.500  0.628  1.0
  Al  Al6  1  0.000  0.500  0.385  1.0
  Al  Al7  1  0.000  0.500  0.751  1.0
  Al  Al8  1  0.000  0.500  0.875  1.0
  O  O9  1  0.000  0.500  0.061  1.0
  O  O10  1  0.000  0.500  0.312  1.0
  O  O11  1  0.000  0.500  0.563  1.0
  O  O12  1  0.000  0.500  0.689  1.0
  O  O13  1  0.000  0.500  0.813  1.0
  O  O14  1  0.000  0.500  0.937  1.0
  O  O15  1  0.500  0.500  0.251  1.0
  O  O16  1  0.500  0.500  0.374  1.0
  O  O17  1  0.500  0.500  0.626  1.0
  O  O18  1  0.500  0.500  0.751  1.0
  O  O19  1  0.500  0.500  0.874  1.0
  O  O20  1  0.000  0.000  1.000  1.0
  O  O21  1  0.000  0.500  0.175  1.0
  O  O22  1  0.000  0.000  0.252  1.0
  O  O23  1  0.000  0.500  0.449  1.0
  O  O24  1  0.000  0.000  0.373  1.0
[/CIF]
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The crystal structure described by CeAl8O16 crystallizes in the orthorhombic Pmm2 space group. Ce(1) is bonded to two equivalent O(14), two equivalent O(16), two equivalent O(7), two equivalent O(8), and four equivalent O(2) atoms to form CeO12 cuboctahedra that share corners with four equivalent Ce(1)O12 cuboctahedra, faces with four equivalent Ce(1)O12 cuboctahedra, faces with four equivalent Al(3)O6 octahedra, and faces with four equivalent Al(6)O6 octahedra. There are eight inequivalent Al sites. In the first Al site, Al(1) is bonded in a square co-planar geometry to one O(1), one O(6), and two equivalent O(12) atoms. In the second Al site, Al(2) is bonded in a linear geometry to one O(1) and one O(13) atom. In the third Al site, Al(3) is bonded to one O(13), one O(2), two equivalent O(14), and two equivalent O(7) atoms to form distorted AlO6 octahedra that share  a cornercorner with one Al(6)O6 octahedra, corners with four equivalent Al(3)O6 octahedra, and faces with four equivalent Ce(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-21°. In the fourth Al site, Al(4) is bonded in a linear geometry to one O(15) and one O(3) atom. In the fifth Al site, Al(5) is bonded in a square co-planar geometry to one O(3), one O(4), and two equivalent O(9) atoms. In the sixth Al site, Al(6) is bonded to one O(15), one O(2), two equivalent O(16), and two equivalent O(8) atoms to form distorted AlO6 octahedra that share  a cornercorner with one Al(3)O6 octahedra, corners with four equivalent Al(6)O6 octahedra, and faces with four equivalent Ce(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-21°. In the seventh Al site, Al(7) is bonded in a square co-planar geometry to one O(4), one O(5), and two equivalent O(10) atoms. In the eighth Al site, Al(8) is bonded in a square co-planar geometry to one O(5), one O(6), and two equivalent O(11) atoms. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one Al(1) and one Al(2) atom. In the second O site, O(2) is bonded to four equivalent Ce(1), one Al(3), and one Al(6) atom to form a mixture of edge and corner-sharing OCe4Al2 octahedra. The corner-sharing octahedra are not tilted. In the third O site, O(3) is bonded in a linear geometry to one Al(4) and one Al(5) atom. In the fourth O site, O(4) is bonded in a linear geometry to one Al(5) and one Al(7) atom. In the fifth O site, O(5) is bonded in a linear geometry to one Al(7) and one Al(8) atom. In the sixth O site, O(6) is bonded in a linear geometry to one Al(1) and one Al(8) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to two equivalent Ce(1) and two equivalent Al(3) atoms. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to two equivalent Ce(1) and two equivalent Al(6) atoms. In the ninth O site, O(9) is bonded in a linear geometry to two equivalent Al(5) atoms. In the tenth O site, O(10) is bonded in a linear geometry to two equivalent Al(7) atoms. In the eleventh O site, O(11) is bonded in a linear geometry to two equivalent Al(8) atoms. In the twelfth O site, O(12) is bonded in a linear geometry to two equivalent Al(1) atoms. In the thirteenth O site, O(13) is bonded in a linear geometry to one Al(2) and one Al(3) atom. In the fourteenth O site, O(14) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ce(1) and two equivalent Al(3) atoms. In the fifteenth O site, O(15) is bonded in a linear geometry to one Al(4) and one Al(6) atom. In the sixteenth O site, O(16) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ce(1) and two equivalent Al(6) atoms. is represented by the CIF file [CIF]
data_CeAl8O16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.590
_cell_length_b   3.676
_cell_length_c   28.494
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   376.075
_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
  Ce  Ce0  1  0.500  0.000  0.312  1.0
  Al  Al1  1  0.000  0.500  0.997  1.0
  Al  Al2  1  0.000  0.500  0.118  1.0
  Al  Al3  1  0.000  0.500  0.240  1.0
  Al  Al4  1  0.000  0.500  0.506  1.0
  Al  Al5  1  0.000  0.500  0.628  1.0
  Al  Al6  1  0.000  0.500  0.385  1.0
  Al  Al7  1  0.000  0.500  0.751  1.0
  Al  Al8  1  0.000  0.500  0.875  1.0
  O  O9  1  0.000  0.500  0.061  1.0
  O  O10  1  0.000  0.500  0.312  1.0
  O  O11  1  0.000  0.500  0.563  1.0
  O  O12  1  0.000  0.500  0.689  1.0
  O  O13  1  0.000  0.500  0.813  1.0
  O  O14  1  0.000  0.500  0.937  1.0
  O  O15  1  0.500  0.500  0.251  1.0
  O  O16  1  0.500  0.500  0.374  1.0
  O  O17  1  0.500  0.500  0.626  1.0
  O  O18  1  0.500  0.500  0.751  1.0
  O  O19  1  0.500  0.500  0.874  1.0
  O  O20  1  0.000  0.000  1.000  1.0
  O  O21  1  0.000  0.500  0.175  1.0
  O  O22  1  0.000  0.000  0.252  1.0
  O  O23  1  0.000  0.500  0.449  1.0
  O  O24  1  0.000  0.000  0.373  1.0
[/CIF]
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