The material structure described by Al11Ce3 crystallizes in the monoclinic Cm space group. There are three inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 12-coordinate geometry to one Al(5), one Al(6), one Al(7), one Al(9), two equivalent Al(10), two equivalent Al(11), two equivalent Al(2), two equivalent Al(4), and two equivalent Al(8) atoms. In the second Ce site, Ce(2) is bonded in a 12-coordinate geometry to one Al(10), one Al(5), one Al(6), one Al(8), two equivalent Al(1), two equivalent Al(11), two equivalent Al(3), two equivalent Al(7), and two equivalent Al(9) atoms. In the third Ce site, Ce(3) is bonded to one Al(10), one Al(7), one Al(8), one Al(9), two equivalent Al(1), two equivalent Al(2), two equivalent Al(3), two equivalent Al(4), two equivalent Al(5), and two equivalent Al(6) atoms to form distorted CeAl16 cuboctahedra that share corners with four equivalent Al(11)Ce4Al8 cuboctahedra, faces with two equivalent Ce(3)Al16 cuboctahedra, faces with two equivalent Al(11)Ce4Al8 cuboctahedra, faces with two equivalent Al(5)Ce4Al8 cuboctahedra, and faces with two equivalent Al(6)Ce4Al8 cuboctahedra. There are eleven inequivalent Al sites. In the first Al site, Al(1) is bonded in a 9-coordinate geometry to two equivalent Ce(2), two equivalent Ce(3), one Al(3), one Al(5), one Al(7), and two equivalent Al(8) atoms. In the second Al site, Al(2) is bonded in a 9-coordinate geometry to two equivalent Ce(1), two equivalent Ce(3), one Al(4), one Al(6), one Al(8), and two equivalent Al(7) atoms. In the third Al site, Al(3) is bonded in a 9-coordinate geometry to two equivalent Ce(2), two equivalent Ce(3), one Al(1), one Al(6), one Al(9), and two equivalent Al(10) atoms. In the fourth Al site, Al(4) is bonded in a 9-coordinate geometry to two equivalent Ce(1), two equivalent Ce(3), one Al(10), one Al(2), one Al(5), and two equivalent Al(9) atoms. In the fifth Al site, Al(5) is bonded to one Ce(1), one Ce(2), two equivalent Ce(3), one Al(1), one Al(4), two equivalent Al(11), two equivalent Al(8), and two equivalent Al(9) atoms to form distorted AlCe4Al8 cuboctahedra that share corners with four equivalent Al(6)Ce4Al8 cuboctahedra,  an edgeedge with one Al(6)Ce4Al8 cuboctahedra,  a faceface with one Al(6)Ce4Al8 cuboctahedra, faces with two equivalent Ce(3)Al16 cuboctahedra, faces with two equivalent Al(11)Ce4Al8 cuboctahedra, and faces with two equivalent Al(5)Ce4Al8 cuboctahedra. In the sixth Al site, Al(6) is bonded to one Ce(1), one Ce(2), two equivalent Ce(3), one Al(2), one Al(3), two equivalent Al(10), two equivalent Al(11), and two equivalent Al(7) atoms to form distorted AlCe4Al8 cuboctahedra that share corners with four equivalent Al(5)Ce4Al8 cuboctahedra,  an edgeedge with one Al(5)Ce4Al8 cuboctahedra,  a faceface with one Al(5)Ce4Al8 cuboctahedra, faces with two equivalent Ce(3)Al16 cuboctahedra, faces with two equivalent Al(11)Ce4Al8 cuboctahedra, and faces with two equivalent Al(6)Ce4Al8 cuboctahedra. In the seventh Al site, Al(7) is bonded in a 10-coordinate geometry to one Ce(1), one Ce(3), two equivalent Ce(2), one Al(1), one Al(11), two equivalent Al(2), and two equivalent Al(6) atoms. In the eighth Al site, Al(8) is bonded in a 10-coordinate geometry to one Ce(2), one Ce(3), two equivalent Ce(1), one Al(11), one Al(2), two equivalent Al(1), and two equivalent Al(5) atoms. In the ninth Al site, Al(9) is bonded in a 10-coordinate geometry to one Ce(1), one Ce(3), two equivalent Ce(2), one Al(11), one Al(3), two equivalent Al(4), and two equivalent Al(5) atoms. In the tenth Al site, Al(10) is bonded in a 10-coordinate geometry to one Ce(2), one Ce(3), two equivalent Ce(1), one Al(11), one Al(4), two equivalent Al(3), and two equivalent Al(6) atoms. In the eleventh Al site, Al(11) is bonded to two equivalent Ce(1), two equivalent Ce(2), one Al(10), one Al(7), one Al(8), one Al(9), two equivalent Al(5), and two equivalent Al(6) atoms to form distorted AlCe4Al8 cuboctahedra that share corners with four equivalent Ce(3)Al16 cuboctahedra, faces with two equivalent Ce(3)Al16 cuboctahedra, faces with two equivalent Al(11)Ce4Al8 cuboctahedra, faces with two equivalent Al(5)Ce4Al8 cuboctahedra, and faces with two equivalent Al(6)Ce4Al8 cuboctahedra. is represented by the CIF file [CIF]
data_Ce3Al11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.490
_cell_length_b   8.467
_cell_length_c   8.466
_cell_angle_alpha   150.170
_cell_angle_beta   107.537
_cell_angle_gamma   80.253
_symmetry_Int_Tables_number   1
_cell_volume   283.141
_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  0.317  0.315  0.001  1.0
  Ce  Ce1  1  0.685  0.686  1.000  1.0
  Ce  Ce2  1  0.000  1.000  0.000  1.0
  Al  Al3  1  0.703  0.335  0.368  1.0
  Al  Al4  1  0.295  0.664  0.631  1.0
  Al  Al5  1  0.967  0.335  0.632  1.0
  Al  Al6  1  0.032  0.665  0.368  1.0
  Al  Al7  1  0.713  0.501  0.213  1.0
  Al  Al8  1  0.288  0.499  0.787  1.0
  Al  Al9  1  0.412  0.136  0.276  1.0
  Al  Al10  1  0.588  0.864  0.724  1.0
  Al  Al11  1  0.860  0.137  0.724  1.0
  Al  Al12  1  0.139  0.863  0.276  1.0
  Al  Al13  1  0.500  0.000  0.500  1.0
[/CIF]
.
The material structure described by Al11Ce3 crystallizes in the monoclinic Cm space group. There are three inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 12-coordinate geometry to one Al(5), one Al(6), one Al(7), one Al(9), two equivalent Al(10), two equivalent Al(11), two equivalent Al(2), two equivalent Al(4), and two equivalent Al(8) atoms. In the second Ce site, Ce(2) is bonded in a 12-coordinate geometry to one Al(10), one Al(5), one Al(6), one Al(8), two equivalent Al(1), two equivalent Al(11), two equivalent Al(3), two equivalent Al(7), and two equivalent Al(9) atoms. In the third Ce site, Ce(3) is bonded to one Al(10), one Al(7), one Al(8), one Al(9), two equivalent Al(1), two equivalent Al(2), two equivalent Al(3), two equivalent Al(4), two equivalent Al(5), and two equivalent Al(6) atoms to form distorted CeAl16 cuboctahedra that share corners with four equivalent Al(11)Ce4Al8 cuboctahedra, faces with two equivalent Ce(3)Al16 cuboctahedra, faces with two equivalent Al(11)Ce4Al8 cuboctahedra, faces with two equivalent Al(5)Ce4Al8 cuboctahedra, and faces with two equivalent Al(6)Ce4Al8 cuboctahedra. There are eleven inequivalent Al sites. In the first Al site, Al(1) is bonded in a 9-coordinate geometry to two equivalent Ce(2), two equivalent Ce(3), one Al(3), one Al(5), one Al(7), and two equivalent Al(8) atoms. In the second Al site, Al(2) is bonded in a 9-coordinate geometry to two equivalent Ce(1), two equivalent Ce(3), one Al(4), one Al(6), one Al(8), and two equivalent Al(7) atoms. In the third Al site, Al(3) is bonded in a 9-coordinate geometry to two equivalent Ce(2), two equivalent Ce(3), one Al(1), one Al(6), one Al(9), and two equivalent Al(10) atoms. In the fourth Al site, Al(4) is bonded in a 9-coordinate geometry to two equivalent Ce(1), two equivalent Ce(3), one Al(10), one Al(2), one Al(5), and two equivalent Al(9) atoms. In the fifth Al site, Al(5) is bonded to one Ce(1), one Ce(2), two equivalent Ce(3), one Al(1), one Al(4), two equivalent Al(11), two equivalent Al(8), and two equivalent Al(9) atoms to form distorted AlCe4Al8 cuboctahedra that share corners with four equivalent Al(6)Ce4Al8 cuboctahedra,  an edgeedge with one Al(6)Ce4Al8 cuboctahedra,  a faceface with one Al(6)Ce4Al8 cuboctahedra, faces with two equivalent Ce(3)Al16 cuboctahedra, faces with two equivalent Al(11)Ce4Al8 cuboctahedra, and faces with two equivalent Al(5)Ce4Al8 cuboctahedra. In the sixth Al site, Al(6) is bonded to one Ce(1), one Ce(2), two equivalent Ce(3), one Al(2), one Al(3), two equivalent Al(10), two equivalent Al(11), and two equivalent Al(7) atoms to form distorted AlCe4Al8 cuboctahedra that share corners with four equivalent Al(5)Ce4Al8 cuboctahedra,  an edgeedge with one Al(5)Ce4Al8 cuboctahedra,  a faceface with one Al(5)Ce4Al8 cuboctahedra, faces with two equivalent Ce(3)Al16 cuboctahedra, faces with two equivalent Al(11)Ce4Al8 cuboctahedra, and faces with two equivalent Al(6)Ce4Al8 cuboctahedra. In the seventh Al site, Al(7) is bonded in a 10-coordinate geometry to one Ce(1), one Ce(3), two equivalent Ce(2), one Al(1), one Al(11), two equivalent Al(2), and two equivalent Al(6) atoms. In the eighth Al site, Al(8) is bonded in a 10-coordinate geometry to one Ce(2), one Ce(3), two equivalent Ce(1), one Al(11), one Al(2), two equivalent Al(1), and two equivalent Al(5) atoms. In the ninth Al site, Al(9) is bonded in a 10-coordinate geometry to one Ce(1), one Ce(3), two equivalent Ce(2), one Al(11), one Al(3), two equivalent Al(4), and two equivalent Al(5) atoms. In the tenth Al site, Al(10) is bonded in a 10-coordinate geometry to one Ce(2), one Ce(3), two equivalent Ce(1), one Al(11), one Al(4), two equivalent Al(3), and two equivalent Al(6) atoms. In the eleventh Al site, Al(11) is bonded to two equivalent Ce(1), two equivalent Ce(2), one Al(10), one Al(7), one Al(8), one Al(9), two equivalent Al(5), and two equivalent Al(6) atoms to form distorted AlCe4Al8 cuboctahedra that share corners with four equivalent Ce(3)Al16 cuboctahedra, faces with two equivalent Ce(3)Al16 cuboctahedra, faces with two equivalent Al(11)Ce4Al8 cuboctahedra, faces with two equivalent Al(5)Ce4Al8 cuboctahedra, and faces with two equivalent Al(6)Ce4Al8 cuboctahedra. is represented by the CIF file [CIF]
data_Ce3Al11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.490
_cell_length_b   8.467
_cell_length_c   8.466
_cell_angle_alpha   150.170
_cell_angle_beta   107.537
_cell_angle_gamma   80.253
_symmetry_Int_Tables_number   1
_cell_volume   283.141
_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  0.317  0.315  0.001  1.0
  Ce  Ce1  1  0.685  0.686  1.000  1.0
  Ce  Ce2  1  0.000  1.000  0.000  1.0
  Al  Al3  1  0.703  0.335  0.368  1.0
  Al  Al4  1  0.295  0.664  0.631  1.0
  Al  Al5  1  0.967  0.335  0.632  1.0
  Al  Al6  1  0.032  0.665  0.368  1.0
  Al  Al7  1  0.713  0.501  0.213  1.0
  Al  Al8  1  0.288  0.499  0.787  1.0
  Al  Al9  1  0.412  0.136  0.276  1.0
  Al  Al10  1  0.588  0.864  0.724  1.0
  Al  Al11  1  0.860  0.137  0.724  1.0
  Al  Al12  1  0.139  0.863  0.276  1.0
  Al  Al13  1  0.500  0.000  0.500  1.0
[/CIF]
.