The crystal structure described by Sm2HfCo16 crystallizes in the trigonal P-3m1 space group. There are two inequivalent Sm sites. In the first Sm site, Sm(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 Sm site, Sm(2) is bonded in a 18-coordinate geometry to six equivalent Co(1), six equivalent Co(4), and six equivalent Co(5) atoms. Hf(1) is bonded in a 14-coordinate geometry to one Sm(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(6) is bonded in a distorted linear geometry to one Sm(1), one Hf(1), three equivalent Co(2), three equivalent Co(4), and six equivalent Co(1) atoms. In the second Co site, Co(1) is bonded in a 12-coordinate geometry to one Sm(1), one Sm(2), one Hf(1), one Co(2), one Co(3), one Co(6), two equivalent Co(1), two equivalent Co(4), and two equivalent Co(5) atoms. In the third Co site, Co(2) is bonded to two equivalent Sm(1), two equivalent Co(6), four equivalent Co(1), and four equivalent Co(4) atoms to form CoSm2Co10 cuboctahedra that share corners with four equivalent Co(3)Sm2Hf2Co8 cuboctahedra, corners with four equivalent Co(4)Sm3Co9 cuboctahedra, corners with six equivalent Co(5)Sm3HfCo8 cuboctahedra, edges with two equivalent Co(4)Sm3Co9 cuboctahedra, edges with four equivalent Co(5)Sm3HfCo8 cuboctahedra, faces with two equivalent Co(3)Sm2Hf2Co8 cuboctahedra, faces with four equivalent Co(2)Sm2Co10 cuboctahedra, and faces with four equivalent Co(4)Sm3Co9 cuboctahedra. In the fourth Co site, Co(3) is bonded to two equivalent Sm(1), two equivalent Hf(1), four equivalent Co(1), and four equivalent Co(5) atoms to form distorted CoSm2Hf2Co8 cuboctahedra that share corners with four equivalent Co(2)Sm2Co10 cuboctahedra, corners with four equivalent Co(5)Sm3HfCo8 cuboctahedra, corners with six equivalent Co(4)Sm3Co9 cuboctahedra, edges with two equivalent Co(5)Sm3HfCo8 cuboctahedra, edges with four equivalent Co(4)Sm3Co9 cuboctahedra, faces with two equivalent Co(2)Sm2Co10 cuboctahedra, faces with four equivalent Co(3)Sm2Hf2Co8 cuboctahedra, and faces with four equivalent Co(5)Sm3HfCo8 cuboctahedra. In the fifth Co site, Co(4) is bonded to one Sm(1), two equivalent Sm(2), one Co(6), two equivalent Co(2), two equivalent Co(4), and four equivalent Co(1) atoms to form distorted CoSm3Co9 cuboctahedra that share corners with two equivalent Co(2)Sm2Co10 cuboctahedra, corners with two equivalent Co(4)Sm3Co9 cuboctahedra, corners with three equivalent Co(3)Sm2Hf2Co8 cuboctahedra, corners with eight equivalent Co(5)Sm3HfCo8 cuboctahedra,  an edgeedge with one Co(2)Sm2Co10 cuboctahedra,  an edgeedge with one Co(4)Sm3Co9 cuboctahedra, edges with two equivalent Co(3)Sm2Hf2Co8 cuboctahedra, edges with four equivalent Co(5)Sm3HfCo8 cuboctahedra, faces with two equivalent Co(2)Sm2Co10 cuboctahedra, faces with two equivalent Co(5)Sm3HfCo8 cuboctahedra, and faces with six equivalent Co(4)Sm3Co9 cuboctahedra. In the sixth Co site, Co(5) is bonded to one Sm(1), two equivalent Sm(2), one Hf(1), two equivalent Co(3), two equivalent Co(5), and four equivalent Co(1) atoms to form distorted CoSm3HfCo8 cuboctahedra that share corners with two equivalent Co(3)Sm2Hf2Co8 cuboctahedra, corners with two equivalent Co(5)Sm3HfCo8 cuboctahedra, corners with three equivalent Co(2)Sm2Co10 cuboctahedra, corners with eight equivalent Co(4)Sm3Co9 cuboctahedra,  an edgeedge with one Co(3)Sm2Hf2Co8 cuboctahedra,  an edgeedge with one Co(5)Sm3HfCo8 cuboctahedra, edges with two equivalent Co(2)Sm2Co10 cuboctahedra, edges with four equivalent Co(4)Sm3Co9 cuboctahedra, faces with two equivalent Co(3)Sm2Hf2Co8 cuboctahedra, faces with two equivalent Co(4)Sm3Co9 cuboctahedra, and faces with six equivalent Co(5)Sm3HfCo8 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sm2HfCo16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.212
_cell_length_b   8.409
_cell_length_c   8.409
_cell_angle_alpha   120.020
_cell_angle_beta   89.997
_cell_angle_gamma   90.003
_symmetry_Int_Tables_number   1
_cell_volume   502.740
_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
  Sm  Sm0  1  0.264  0.667  0.333  1.0
  Sm  Sm1  1  0.736  0.333  0.667  1.0
  Sm  Sm2  1  0.750  0.000  1.000  1.0
  Sm  Sm3  1  0.250  1.000  0.000  1.0
  Hf  Hf4  1  0.114  0.333  0.667  1.0
  Hf  Hf5  1  0.886  0.667  0.333  1.0
  Co  Co6  1  0.748  0.671  0.040  1.0
  Co  Co7  1  0.748  0.370  0.329  1.0
  Co  Co8  1  0.749  0.960  0.630  1.0
  Co  Co9  1  0.749  0.370  0.040  1.0
  Co  Co10  1  0.748  0.960  0.329  1.0
  Co  Co11  1  0.748  0.671  0.630  1.0
  Co  Co12  1  0.252  0.329  0.960  1.0
  Co  Co13  1  0.252  0.630  0.671  1.0
  Co  Co14  1  0.251  0.040  0.370  1.0
  Co  Co15  1  0.251  0.630  0.960  1.0
  Co  Co16  1  0.252  0.040  0.671  1.0
  Co  Co17  1  0.252  0.329  0.370  1.0
  Co  Co18  1  0.500  0.500  0.000  1.0
  Co  Co19  1  0.500  0.500  0.500  1.0
  Co  Co20  1  0.500  0.000  0.500  1.0
  Co  Co21  1  0.000  0.500  0.000  1.0
  Co  Co22  1  0.000  0.500  0.500  1.0
  Co  Co23  1  0.000  0.000  0.500  1.0
  Co  Co24  1  0.485  0.834  0.667  1.0
  Co  Co25  1  0.485  0.833  0.167  1.0
  Co  Co26  1  0.485  0.333  0.166  1.0
  Co  Co27  1  0.515  0.166  0.333  1.0
  Co  Co28  1  0.515  0.167  0.833  1.0
  Co  Co29  1  0.515  0.667  0.834  1.0
  Co  Co30  1  0.980  0.163  0.326  1.0
  Co  Co31  1  0.980  0.163  0.837  1.0
  Co  Co32  1  0.980  0.674  0.837  1.0
  Co  Co33  1  0.020  0.837  0.674  1.0
  Co  Co34  1  0.020  0.837  0.163  1.0
  Co  Co35  1  0.020  0.326  0.163  1.0
  Co  Co36  1  0.594  0.667  0.333  1.0
  Co  Co37  1  0.406  0.333  0.667  1.0
[/CIF]
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The crystal structure described by Sm2HfCo16 crystallizes in the trigonal P-3m1 space group. There are two inequivalent Sm sites. In the first Sm site, Sm(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 Sm site, Sm(2) is bonded in a 18-coordinate geometry to six equivalent Co(1), six equivalent Co(4), and six equivalent Co(5) atoms. Hf(1) is bonded in a 14-coordinate geometry to one Sm(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(6) is bonded in a distorted linear geometry to one Sm(1), one Hf(1), three equivalent Co(2), three equivalent Co(4), and six equivalent Co(1) atoms. In the second Co site, Co(1) is bonded in a 12-coordinate geometry to one Sm(1), one Sm(2), one Hf(1), one Co(2), one Co(3), one Co(6), two equivalent Co(1), two equivalent Co(4), and two equivalent Co(5) atoms. In the third Co site, Co(2) is bonded to two equivalent Sm(1), two equivalent Co(6), four equivalent Co(1), and four equivalent Co(4) atoms to form CoSm2Co10 cuboctahedra that share corners with four equivalent Co(3)Sm2Hf2Co8 cuboctahedra, corners with four equivalent Co(4)Sm3Co9 cuboctahedra, corners with six equivalent Co(5)Sm3HfCo8 cuboctahedra, edges with two equivalent Co(4)Sm3Co9 cuboctahedra, edges with four equivalent Co(5)Sm3HfCo8 cuboctahedra, faces with two equivalent Co(3)Sm2Hf2Co8 cuboctahedra, faces with four equivalent Co(2)Sm2Co10 cuboctahedra, and faces with four equivalent Co(4)Sm3Co9 cuboctahedra. In the fourth Co site, Co(3) is bonded to two equivalent Sm(1), two equivalent Hf(1), four equivalent Co(1), and four equivalent Co(5) atoms to form distorted CoSm2Hf2Co8 cuboctahedra that share corners with four equivalent Co(2)Sm2Co10 cuboctahedra, corners with four equivalent Co(5)Sm3HfCo8 cuboctahedra, corners with six equivalent Co(4)Sm3Co9 cuboctahedra, edges with two equivalent Co(5)Sm3HfCo8 cuboctahedra, edges with four equivalent Co(4)Sm3Co9 cuboctahedra, faces with two equivalent Co(2)Sm2Co10 cuboctahedra, faces with four equivalent Co(3)Sm2Hf2Co8 cuboctahedra, and faces with four equivalent Co(5)Sm3HfCo8 cuboctahedra. In the fifth Co site, Co(4) is bonded to one Sm(1), two equivalent Sm(2), one Co(6), two equivalent Co(2), two equivalent Co(4), and four equivalent Co(1) atoms to form distorted CoSm3Co9 cuboctahedra that share corners with two equivalent Co(2)Sm2Co10 cuboctahedra, corners with two equivalent Co(4)Sm3Co9 cuboctahedra, corners with three equivalent Co(3)Sm2Hf2Co8 cuboctahedra, corners with eight equivalent Co(5)Sm3HfCo8 cuboctahedra,  an edgeedge with one Co(2)Sm2Co10 cuboctahedra,  an edgeedge with one Co(4)Sm3Co9 cuboctahedra, edges with two equivalent Co(3)Sm2Hf2Co8 cuboctahedra, edges with four equivalent Co(5)Sm3HfCo8 cuboctahedra, faces with two equivalent Co(2)Sm2Co10 cuboctahedra, faces with two equivalent Co(5)Sm3HfCo8 cuboctahedra, and faces with six equivalent Co(4)Sm3Co9 cuboctahedra. In the sixth Co site, Co(5) is bonded to one Sm(1), two equivalent Sm(2), one Hf(1), two equivalent Co(3), two equivalent Co(5), and four equivalent Co(1) atoms to form distorted CoSm3HfCo8 cuboctahedra that share corners with two equivalent Co(3)Sm2Hf2Co8 cuboctahedra, corners with two equivalent Co(5)Sm3HfCo8 cuboctahedra, corners with three equivalent Co(2)Sm2Co10 cuboctahedra, corners with eight equivalent Co(4)Sm3Co9 cuboctahedra,  an edgeedge with one Co(3)Sm2Hf2Co8 cuboctahedra,  an edgeedge with one Co(5)Sm3HfCo8 cuboctahedra, edges with two equivalent Co(2)Sm2Co10 cuboctahedra, edges with four equivalent Co(4)Sm3Co9 cuboctahedra, faces with two equivalent Co(3)Sm2Hf2Co8 cuboctahedra, faces with two equivalent Co(4)Sm3Co9 cuboctahedra, and faces with six equivalent Co(5)Sm3HfCo8 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sm2HfCo16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.212
_cell_length_b   8.409
_cell_length_c   8.409
_cell_angle_alpha   120.020
_cell_angle_beta   89.997
_cell_angle_gamma   90.003
_symmetry_Int_Tables_number   1
_cell_volume   502.740
_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
  Sm  Sm0  1  0.264  0.667  0.333  1.0
  Sm  Sm1  1  0.736  0.333  0.667  1.0
  Sm  Sm2  1  0.750  0.000  1.000  1.0
  Sm  Sm3  1  0.250  1.000  0.000  1.0
  Hf  Hf4  1  0.114  0.333  0.667  1.0
  Hf  Hf5  1  0.886  0.667  0.333  1.0
  Co  Co6  1  0.748  0.671  0.040  1.0
  Co  Co7  1  0.748  0.370  0.329  1.0
  Co  Co8  1  0.749  0.960  0.630  1.0
  Co  Co9  1  0.749  0.370  0.040  1.0
  Co  Co10  1  0.748  0.960  0.329  1.0
  Co  Co11  1  0.748  0.671  0.630  1.0
  Co  Co12  1  0.252  0.329  0.960  1.0
  Co  Co13  1  0.252  0.630  0.671  1.0
  Co  Co14  1  0.251  0.040  0.370  1.0
  Co  Co15  1  0.251  0.630  0.960  1.0
  Co  Co16  1  0.252  0.040  0.671  1.0
  Co  Co17  1  0.252  0.329  0.370  1.0
  Co  Co18  1  0.500  0.500  0.000  1.0
  Co  Co19  1  0.500  0.500  0.500  1.0
  Co  Co20  1  0.500  0.000  0.500  1.0
  Co  Co21  1  0.000  0.500  0.000  1.0
  Co  Co22  1  0.000  0.500  0.500  1.0
  Co  Co23  1  0.000  0.000  0.500  1.0
  Co  Co24  1  0.485  0.834  0.667  1.0
  Co  Co25  1  0.485  0.833  0.167  1.0
  Co  Co26  1  0.485  0.333  0.166  1.0
  Co  Co27  1  0.515  0.166  0.333  1.0
  Co  Co28  1  0.515  0.167  0.833  1.0
  Co  Co29  1  0.515  0.667  0.834  1.0
  Co  Co30  1  0.980  0.163  0.326  1.0
  Co  Co31  1  0.980  0.163  0.837  1.0
  Co  Co32  1  0.980  0.674  0.837  1.0
  Co  Co33  1  0.020  0.837  0.674  1.0
  Co  Co34  1  0.020  0.837  0.163  1.0
  Co  Co35  1  0.020  0.326  0.163  1.0
  Co  Co36  1  0.594  0.667  0.333  1.0
  Co  Co37  1  0.406  0.333  0.667  1.0
[/CIF]
.