The structure described by SmNi3 crystallizes in the monoclinic C2/m space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 12-coordinate geometry to three equivalent Ni(2), three equivalent Ni(4), and six equivalent Ni(1) atoms. In the second Sm site, Sm(2) is bonded in a 6-coordinate geometry to four equivalent Ni(2), six equivalent Ni(3), and eight equivalent Ni(1) atoms. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent Sm(2), three equivalent Sm(1), one Ni(4), two equivalent Ni(1), two equivalent Ni(2), and two equivalent Ni(3) atoms to form NiSm5Ni7 cuboctahedra that share corners with two equivalent Ni(4)Sm6Ni6 cuboctahedra, corners with four equivalent Ni(2)Sm5Ni7 cuboctahedra, corners with eleven equivalent Ni(1)Sm5Ni7 cuboctahedra, edges with two equivalent Ni(2)Sm5Ni7 cuboctahedra, edges with six equivalent Ni(1)Sm5Ni7 cuboctahedra, faces with three equivalent Ni(4)Sm6Ni6 cuboctahedra, faces with five equivalent Ni(2)Sm5Ni7 cuboctahedra, and faces with six equivalent Ni(1)Sm5Ni7 cuboctahedra. In the second Ni site, Ni(2) is bonded to two equivalent Sm(2), three equivalent Sm(1), one Ni(4), two equivalent Ni(3), and four equivalent Ni(1) atoms to form NiSm5Ni7 cuboctahedra that share corners with two equivalent Ni(4)Sm6Ni6 cuboctahedra, corners with seven equivalent Ni(2)Sm5Ni7 cuboctahedra, corners with eight equivalent Ni(1)Sm5Ni7 cuboctahedra, edges with four equivalent Ni(1)Sm5Ni7 cuboctahedra, edges with four equivalent Ni(2)Sm5Ni7 cuboctahedra,  a faceface with one Ni(2)Sm5Ni7 cuboctahedra, faces with three equivalent Ni(4)Sm6Ni6 cuboctahedra, and faces with ten equivalent Ni(1)Sm5Ni7 cuboctahedra. In the third Ni site, Ni(3) is bonded in a 9-coordinate geometry to three equivalent Sm(2), two equivalent Ni(2), and four equivalent Ni(1) atoms. In the fourth Ni site, Ni(4) is bonded to six equivalent Sm(1), two equivalent Ni(2), and four equivalent Ni(1) atoms to form NiSm6Ni6 cuboctahedra that share corners with four equivalent Ni(2)Sm5Ni7 cuboctahedra, corners with eight equivalent Ni(1)Sm5Ni7 cuboctahedra, edges with six equivalent Ni(4)Sm6Ni6 cuboctahedra, faces with six equivalent Ni(2)Sm5Ni7 cuboctahedra, and faces with twelve equivalent Ni(1)Sm5Ni7 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_SmNi3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.966
_cell_length_b   4.966
_cell_length_c   8.598
_cell_angle_alpha   73.241
_cell_angle_beta   73.241
_cell_angle_gamma   60.028
_symmetry_Int_Tables_number   1
_cell_volume   173.187
_cell_formula_units_Z   3
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  0.139  0.139  0.584  1.0
  Sm  Sm1  1  0.861  0.861  0.416  1.0
  Sm  Sm2  1  0.000  0.000  0.000  1.0
  Ni  Ni3  1  0.081  0.581  0.758  1.0
  Ni  Ni4  1  0.581  0.581  0.758  1.0
  Ni  Ni5  1  0.581  0.081  0.758  1.0
  Ni  Ni6  1  0.919  0.419  0.242  1.0
  Ni  Ni7  1  0.419  0.419  0.242  1.0
  Ni  Ni8  1  0.419  0.919  0.242  1.0
  Ni  Ni9  1  0.333  0.333  0.001  1.0
  Ni  Ni10  1  0.667  0.667  0.999  1.0
  Ni  Ni11  1  0.500  0.500  0.500  1.0
[/CIF]
.
The structure described by SmNi3 crystallizes in the monoclinic C2/m space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 12-coordinate geometry to three equivalent Ni(2), three equivalent Ni(4), and six equivalent Ni(1) atoms. In the second Sm site, Sm(2) is bonded in a 6-coordinate geometry to four equivalent Ni(2), six equivalent Ni(3), and eight equivalent Ni(1) atoms. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent Sm(2), three equivalent Sm(1), one Ni(4), two equivalent Ni(1), two equivalent Ni(2), and two equivalent Ni(3) atoms to form NiSm5Ni7 cuboctahedra that share corners with two equivalent Ni(4)Sm6Ni6 cuboctahedra, corners with four equivalent Ni(2)Sm5Ni7 cuboctahedra, corners with eleven equivalent Ni(1)Sm5Ni7 cuboctahedra, edges with two equivalent Ni(2)Sm5Ni7 cuboctahedra, edges with six equivalent Ni(1)Sm5Ni7 cuboctahedra, faces with three equivalent Ni(4)Sm6Ni6 cuboctahedra, faces with five equivalent Ni(2)Sm5Ni7 cuboctahedra, and faces with six equivalent Ni(1)Sm5Ni7 cuboctahedra. In the second Ni site, Ni(2) is bonded to two equivalent Sm(2), three equivalent Sm(1), one Ni(4), two equivalent Ni(3), and four equivalent Ni(1) atoms to form NiSm5Ni7 cuboctahedra that share corners with two equivalent Ni(4)Sm6Ni6 cuboctahedra, corners with seven equivalent Ni(2)Sm5Ni7 cuboctahedra, corners with eight equivalent Ni(1)Sm5Ni7 cuboctahedra, edges with four equivalent Ni(1)Sm5Ni7 cuboctahedra, edges with four equivalent Ni(2)Sm5Ni7 cuboctahedra,  a faceface with one Ni(2)Sm5Ni7 cuboctahedra, faces with three equivalent Ni(4)Sm6Ni6 cuboctahedra, and faces with ten equivalent Ni(1)Sm5Ni7 cuboctahedra. In the third Ni site, Ni(3) is bonded in a 9-coordinate geometry to three equivalent Sm(2), two equivalent Ni(2), and four equivalent Ni(1) atoms. In the fourth Ni site, Ni(4) is bonded to six equivalent Sm(1), two equivalent Ni(2), and four equivalent Ni(1) atoms to form NiSm6Ni6 cuboctahedra that share corners with four equivalent Ni(2)Sm5Ni7 cuboctahedra, corners with eight equivalent Ni(1)Sm5Ni7 cuboctahedra, edges with six equivalent Ni(4)Sm6Ni6 cuboctahedra, faces with six equivalent Ni(2)Sm5Ni7 cuboctahedra, and faces with twelve equivalent Ni(1)Sm5Ni7 cuboctahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_SmNi3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.966
_cell_length_b   4.966
_cell_length_c   8.598
_cell_angle_alpha   73.241
_cell_angle_beta   73.241
_cell_angle_gamma   60.028
_symmetry_Int_Tables_number   1
_cell_volume   173.187
_cell_formula_units_Z   3
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  0.139  0.139  0.584  1.0
  Sm  Sm1  1  0.861  0.861  0.416  1.0
  Sm  Sm2  1  0.000  0.000  0.000  1.0
  Ni  Ni3  1  0.081  0.581  0.758  1.0
  Ni  Ni4  1  0.581  0.581  0.758  1.0
  Ni  Ni5  1  0.581  0.081  0.758  1.0
  Ni  Ni6  1  0.919  0.419  0.242  1.0
  Ni  Ni7  1  0.419  0.419  0.242  1.0
  Ni  Ni8  1  0.419  0.919  0.242  1.0
  Ni  Ni9  1  0.333  0.333  0.001  1.0
  Ni  Ni10  1  0.667  0.667  0.999  1.0
  Ni  Ni11  1  0.500  0.500  0.500  1.0
[/CIF]
.