The material structure described by Ce2HfCo16 crystallizes in the trigonal P-3m1 space group. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 20-coordinate geometry to one Hf(1), one Co(6), three equivalent Co(2), three equivalent Co(3), three equivalent Co(4), three equivalent Co(5), and six equivalent Co(1) atoms. In the second Ce site, Ce(2) is bonded in a 18-coordinate geometry to six equivalent Co(1), six equivalent Co(2), and six equivalent Co(3) atoms. Hf(1) is bonded in a 14-coordinate geometry to one Ce(1), one Co(6), three equivalent Co(3), three equivalent Co(5), and six equivalent Co(1) atoms. There are six inequivalent Co sites. In the first Co site, Co(5) is bonded in a 12-coordinate geometry to two equivalent Ce(1), two equivalent Hf(1), four equivalent Co(1), and four equivalent Co(3) atoms. In the second Co site, Co(6) is bonded in a distorted linear geometry to one Ce(1), one Hf(1), three equivalent Co(2), and three equivalent Co(4) atoms. In the third Co site, Co(1) is bonded in a 11-coordinate geometry to one Ce(1), one Ce(2), one Hf(1), one Co(4), one Co(5), two equivalent Co(1), two equivalent Co(2), and two equivalent Co(3) atoms. In the fourth Co site, Co(2) is bonded to one Ce(1), two equivalent Ce(2), one Co(6), two equivalent Co(2), two equivalent Co(4), and four equivalent Co(1) atoms to form distorted CoCe3Co9 cuboctahedra that share corners with two equivalent Co(4)Ce2Co10 cuboctahedra, corners with two equivalent Co(2)Ce3Co9 cuboctahedra, corners with eight equivalent Co(3)Ce3HfCo8 cuboctahedra,  an edgeedge with one Co(4)Ce2Co10 cuboctahedra,  an edgeedge with one Co(2)Ce3Co9 cuboctahedra, edges with four equivalent Co(3)Ce3HfCo8 cuboctahedra, faces with two equivalent Co(4)Ce2Co10 cuboctahedra, faces with two equivalent Co(3)Ce3HfCo8 cuboctahedra, and faces with six equivalent Co(2)Ce3Co9 cuboctahedra. In the fifth Co site, Co(3) is bonded to one Ce(1), two equivalent Ce(2), one Hf(1), two equivalent Co(3), two equivalent Co(5), and four equivalent Co(1) atoms to form distorted CoCe3HfCo8 cuboctahedra that share corners with two equivalent Co(3)Ce3HfCo8 cuboctahedra, corners with three equivalent Co(4)Ce2Co10 cuboctahedra, corners with eight equivalent Co(2)Ce3Co9 cuboctahedra,  an edgeedge with one Co(3)Ce3HfCo8 cuboctahedra, edges with two equivalent Co(4)Ce2Co10 cuboctahedra, edges with four equivalent Co(2)Ce3Co9 cuboctahedra, faces with two equivalent Co(2)Ce3Co9 cuboctahedra, and faces with six equivalent Co(3)Ce3HfCo8 cuboctahedra. In the sixth Co site, Co(4) is bonded to two equivalent Ce(1), two equivalent Co(6), four equivalent Co(1), and four equivalent Co(2) atoms to form CoCe2Co10 cuboctahedra that share corners with four equivalent Co(2)Ce3Co9 cuboctahedra, corners with six equivalent Co(3)Ce3HfCo8 cuboctahedra, edges with two equivalent Co(2)Ce3Co9 cuboctahedra, edges with four equivalent Co(3)Ce3HfCo8 cuboctahedra, faces with four equivalent Co(4)Ce2Co10 cuboctahedra, and faces with four equivalent Co(2)Ce3Co9 cuboctahedra. is represented by the CIF file [CIF]
data_Ce2HfCo16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.327
_cell_length_b   8.327
_cell_length_c   8.240
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   494.860
_cell_formula_units_Z   2
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  0.667  0.333  0.734  1.0
  Ce  Ce1  1  0.333  0.667  0.266  1.0
  Ce  Ce2  1  0.000  0.000  0.249  1.0
  Ce  Ce3  1  0.000  0.000  0.751  1.0
  Hf  Hf4  1  0.333  0.667  0.881  1.0
  Hf  Hf5  1  0.667  0.333  0.119  1.0
  Co  Co6  1  0.967  0.327  0.251  1.0
  Co  Co7  1  0.673  0.640  0.251  1.0
  Co  Co8  1  0.360  0.033  0.251  1.0
  Co  Co9  1  0.967  0.640  0.251  1.0
  Co  Co10  1  0.673  0.033  0.251  1.0
  Co  Co11  1  0.360  0.327  0.251  1.0
  Co  Co12  1  0.033  0.673  0.749  1.0
  Co  Co13  1  0.327  0.360  0.749  1.0
  Co  Co14  1  0.640  0.967  0.749  1.0
  Co  Co15  1  0.033  0.360  0.749  1.0
  Co  Co16  1  0.327  0.967  0.749  1.0
  Co  Co17  1  0.640  0.673  0.749  1.0
  Co  Co18  1  0.333  0.167  0.512  1.0
  Co  Co19  1  0.833  0.167  0.512  1.0
  Co  Co20  1  0.833  0.667  0.512  1.0
  Co  Co21  1  0.667  0.833  0.488  1.0
  Co  Co22  1  0.167  0.833  0.488  1.0
  Co  Co23  1  0.167  0.333  0.488  1.0
  Co  Co24  1  0.672  0.836  0.022  1.0
  Co  Co25  1  0.164  0.836  0.022  1.0
  Co  Co26  1  0.164  0.328  0.022  1.0
  Co  Co27  1  0.328  0.164  0.978  1.0
  Co  Co28  1  0.836  0.164  0.978  1.0
  Co  Co29  1  0.836  0.672  0.978  1.0
  Co  Co30  1  0.000  0.500  0.500  1.0
  Co  Co31  1  0.500  0.500  0.500  1.0
  Co  Co32  1  0.500  0.000  0.500  1.0
  Co  Co33  1  0.000  0.500  0.000  1.0
  Co  Co34  1  0.500  0.500  0.000  1.0
  Co  Co35  1  0.500  0.000  0.000  1.0
  Co  Co36  1  0.667  0.333  0.411  1.0
  Co  Co37  1  0.333  0.667  0.589  1.0
[/CIF]
.
The material structure described by Ce2HfCo16 crystallizes in the trigonal P-3m1 space group. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 20-coordinate geometry to one Hf(1), one Co(6), three equivalent Co(2), three equivalent Co(3), three equivalent Co(4), three equivalent Co(5), and six equivalent Co(1) atoms. In the second Ce site, Ce(2) is bonded in a 18-coordinate geometry to six equivalent Co(1), six equivalent Co(2), and six equivalent Co(3) atoms. Hf(1) is bonded in a 14-coordinate geometry to one Ce(1), one Co(6), three equivalent Co(3), three equivalent Co(5), and six equivalent Co(1) atoms. There are six inequivalent Co sites. In the first Co site, Co(5) is bonded in a 12-coordinate geometry to two equivalent Ce(1), two equivalent Hf(1), four equivalent Co(1), and four equivalent Co(3) atoms. In the second Co site, Co(6) is bonded in a distorted linear geometry to one Ce(1), one Hf(1), three equivalent Co(2), and three equivalent Co(4) atoms. In the third Co site, Co(1) is bonded in a 11-coordinate geometry to one Ce(1), one Ce(2), one Hf(1), one Co(4), one Co(5), two equivalent Co(1), two equivalent Co(2), and two equivalent Co(3) atoms. In the fourth Co site, Co(2) is bonded to one Ce(1), two equivalent Ce(2), one Co(6), two equivalent Co(2), two equivalent Co(4), and four equivalent Co(1) atoms to form distorted CoCe3Co9 cuboctahedra that share corners with two equivalent Co(4)Ce2Co10 cuboctahedra, corners with two equivalent Co(2)Ce3Co9 cuboctahedra, corners with eight equivalent Co(3)Ce3HfCo8 cuboctahedra,  an edgeedge with one Co(4)Ce2Co10 cuboctahedra,  an edgeedge with one Co(2)Ce3Co9 cuboctahedra, edges with four equivalent Co(3)Ce3HfCo8 cuboctahedra, faces with two equivalent Co(4)Ce2Co10 cuboctahedra, faces with two equivalent Co(3)Ce3HfCo8 cuboctahedra, and faces with six equivalent Co(2)Ce3Co9 cuboctahedra. In the fifth Co site, Co(3) is bonded to one Ce(1), two equivalent Ce(2), one Hf(1), two equivalent Co(3), two equivalent Co(5), and four equivalent Co(1) atoms to form distorted CoCe3HfCo8 cuboctahedra that share corners with two equivalent Co(3)Ce3HfCo8 cuboctahedra, corners with three equivalent Co(4)Ce2Co10 cuboctahedra, corners with eight equivalent Co(2)Ce3Co9 cuboctahedra,  an edgeedge with one Co(3)Ce3HfCo8 cuboctahedra, edges with two equivalent Co(4)Ce2Co10 cuboctahedra, edges with four equivalent Co(2)Ce3Co9 cuboctahedra, faces with two equivalent Co(2)Ce3Co9 cuboctahedra, and faces with six equivalent Co(3)Ce3HfCo8 cuboctahedra. In the sixth Co site, Co(4) is bonded to two equivalent Ce(1), two equivalent Co(6), four equivalent Co(1), and four equivalent Co(2) atoms to form CoCe2Co10 cuboctahedra that share corners with four equivalent Co(2)Ce3Co9 cuboctahedra, corners with six equivalent Co(3)Ce3HfCo8 cuboctahedra, edges with two equivalent Co(2)Ce3Co9 cuboctahedra, edges with four equivalent Co(3)Ce3HfCo8 cuboctahedra, faces with four equivalent Co(4)Ce2Co10 cuboctahedra, and faces with four equivalent Co(2)Ce3Co9 cuboctahedra. is represented by the CIF file [CIF]
data_Ce2HfCo16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.327
_cell_length_b   8.327
_cell_length_c   8.240
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   494.860
_cell_formula_units_Z   2
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  0.667  0.333  0.734  1.0
  Ce  Ce1  1  0.333  0.667  0.266  1.0
  Ce  Ce2  1  0.000  0.000  0.249  1.0
  Ce  Ce3  1  0.000  0.000  0.751  1.0
  Hf  Hf4  1  0.333  0.667  0.881  1.0
  Hf  Hf5  1  0.667  0.333  0.119  1.0
  Co  Co6  1  0.967  0.327  0.251  1.0
  Co  Co7  1  0.673  0.640  0.251  1.0
  Co  Co8  1  0.360  0.033  0.251  1.0
  Co  Co9  1  0.967  0.640  0.251  1.0
  Co  Co10  1  0.673  0.033  0.251  1.0
  Co  Co11  1  0.360  0.327  0.251  1.0
  Co  Co12  1  0.033  0.673  0.749  1.0
  Co  Co13  1  0.327  0.360  0.749  1.0
  Co  Co14  1  0.640  0.967  0.749  1.0
  Co  Co15  1  0.033  0.360  0.749  1.0
  Co  Co16  1  0.327  0.967  0.749  1.0
  Co  Co17  1  0.640  0.673  0.749  1.0
  Co  Co18  1  0.333  0.167  0.512  1.0
  Co  Co19  1  0.833  0.167  0.512  1.0
  Co  Co20  1  0.833  0.667  0.512  1.0
  Co  Co21  1  0.667  0.833  0.488  1.0
  Co  Co22  1  0.167  0.833  0.488  1.0
  Co  Co23  1  0.167  0.333  0.488  1.0
  Co  Co24  1  0.672  0.836  0.022  1.0
  Co  Co25  1  0.164  0.836  0.022  1.0
  Co  Co26  1  0.164  0.328  0.022  1.0
  Co  Co27  1  0.328  0.164  0.978  1.0
  Co  Co28  1  0.836  0.164  0.978  1.0
  Co  Co29  1  0.836  0.672  0.978  1.0
  Co  Co30  1  0.000  0.500  0.500  1.0
  Co  Co31  1  0.500  0.500  0.500  1.0
  Co  Co32  1  0.500  0.000  0.500  1.0
  Co  Co33  1  0.000  0.500  0.000  1.0
  Co  Co34  1  0.500  0.500  0.000  1.0
  Co  Co35  1  0.500  0.000  0.000  1.0
  Co  Co36  1  0.667  0.333  0.411  1.0
  Co  Co37  1  0.333  0.667  0.589  1.0
[/CIF]
.