The material described by Sm2Ni7 crystallizes in the hexagonal P6_3/mmc 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(1) and nine equivalent Ni(3) atoms. In the second Sm site, Sm(2) is bonded in a 18-coordinate geometry to three equivalent Ni(4), three equivalent Ni(5), six equivalent Ni(2), and six equivalent Ni(3) atoms. There are five inequivalent Ni sites. In the first Ni site, Ni(5) is bonded in a 9-coordinate geometry to three equivalent Sm(2), three equivalent Ni(2), and three equivalent Ni(3) atoms. In the second Ni site, Ni(1) is bonded to six equivalent Sm(1) and six equivalent Ni(3) atoms to form NiSm6Ni6 cuboctahedra that share corners with twelve equivalent Ni(3)Sm5Ni7 cuboctahedra, edges with six equivalent Ni(1)Sm6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(3)Sm5Ni7 cuboctahedra. In the third Ni site, Ni(2) is bonded to four equivalent Sm(2), two equivalent Ni(4), two equivalent Ni(5), and four equivalent Ni(2) atoms to form NiSm4Ni8 cuboctahedra that share corners with four equivalent Ni(2)Sm4Ni8 cuboctahedra, corners with twelve equivalent Ni(3)Sm5Ni7 cuboctahedra, edges with two equivalent Ni(2)Sm4Ni8 cuboctahedra, edges with eight equivalent Ni(3)Sm5Ni7 cuboctahedra, faces with two equivalent Ni(3)Sm5Ni7 cuboctahedra, and faces with eight equivalent Ni(2)Sm4Ni8 cuboctahedra. In the fourth Ni site, Ni(3) is bonded to two equivalent Sm(2), three equivalent Sm(1), one Ni(1), one Ni(4), one Ni(5), and four equivalent Ni(3) atoms to form distorted NiSm5Ni7 cuboctahedra that share corners with two equivalent Ni(1)Sm6Ni6 cuboctahedra, corners with six equivalent Ni(2)Sm4Ni8 cuboctahedra, corners with nine equivalent Ni(3)Sm5Ni7 cuboctahedra, edges with four equivalent Ni(2)Sm4Ni8 cuboctahedra, edges with four equivalent Ni(3)Sm5Ni7 cuboctahedra,  a faceface with one Ni(2)Sm4Ni8 cuboctahedra, faces with three equivalent Ni(1)Sm6Ni6 cuboctahedra, and faces with ten equivalent Ni(3)Sm5Ni7 cuboctahedra. In the fifth Ni site, Ni(4) is bonded in a 9-coordinate geometry to three equivalent Sm(2), three equivalent Ni(2), and three equivalent Ni(3) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sm2Ni7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.929
_cell_length_b   4.929
_cell_length_c   24.131
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   119.997
_symmetry_Int_Tables_number   1
_cell_volume   507.697
_cell_formula_units_Z   4
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  0.667  0.333  0.530  1.0
  Sm  Sm1  1  0.333  0.667  0.470  1.0
  Sm  Sm2  1  0.333  0.667  0.030  1.0
  Sm  Sm3  1  0.667  0.333  0.970  1.0
  Sm  Sm4  1  0.667  0.333  0.674  1.0
  Sm  Sm5  1  0.333  0.667  0.326  1.0
  Sm  Sm6  1  0.333  0.667  0.174  1.0
  Sm  Sm7  1  0.667  0.333  0.826  1.0
  Ni  Ni8  1  0.000  0.000  0.500  1.0
  Ni  Ni9  1  0.000  0.000  0.000  1.0
  Ni  Ni10  1  0.167  0.334  0.750  1.0
  Ni  Ni11  1  0.167  0.833  0.750  1.0
  Ni  Ni12  1  0.666  0.833  0.750  1.0
  Ni  Ni13  1  0.833  0.666  0.250  1.0
  Ni  Ni14  1  0.833  0.167  0.250  1.0
  Ni  Ni15  1  0.334  0.167  0.250  1.0
  Ni  Ni16  1  0.166  0.333  0.587  1.0
  Ni  Ni17  1  0.166  0.834  0.587  1.0
  Ni  Ni18  1  0.667  0.834  0.587  1.0
  Ni  Ni19  1  0.834  0.667  0.413  1.0
  Ni  Ni20  1  0.834  0.166  0.413  1.0
  Ni  Ni21  1  0.333  0.166  0.413  1.0
  Ni  Ni22  1  0.834  0.667  0.087  1.0
  Ni  Ni23  1  0.834  0.166  0.087  1.0
  Ni  Ni24  1  0.333  0.166  0.087  1.0
  Ni  Ni25  1  0.166  0.333  0.913  1.0
  Ni  Ni26  1  0.166  0.834  0.913  1.0
  Ni  Ni27  1  0.667  0.834  0.913  1.0
  Ni  Ni28  1  0.000  1.000  0.669  1.0
  Ni  Ni29  1  1.000  0.000  0.331  1.0
  Ni  Ni30  1  1.000  0.000  0.169  1.0
  Ni  Ni31  1  0.000  1.000  0.831  1.0
  Ni  Ni32  1  0.667  0.333  0.332  1.0
  Ni  Ni33  1  0.333  0.667  0.668  1.0
  Ni  Ni34  1  0.333  0.667  0.832  1.0
  Ni  Ni35  1  0.667  0.333  0.168  1.0
[/CIF]
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The material described by Sm2Ni7 crystallizes in the hexagonal P6_3/mmc 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(1) and nine equivalent Ni(3) atoms. In the second Sm site, Sm(2) is bonded in a 18-coordinate geometry to three equivalent Ni(4), three equivalent Ni(5), six equivalent Ni(2), and six equivalent Ni(3) atoms. There are five inequivalent Ni sites. In the first Ni site, Ni(5) is bonded in a 9-coordinate geometry to three equivalent Sm(2), three equivalent Ni(2), and three equivalent Ni(3) atoms. In the second Ni site, Ni(1) is bonded to six equivalent Sm(1) and six equivalent Ni(3) atoms to form NiSm6Ni6 cuboctahedra that share corners with twelve equivalent Ni(3)Sm5Ni7 cuboctahedra, edges with six equivalent Ni(1)Sm6Ni6 cuboctahedra, and faces with eighteen equivalent Ni(3)Sm5Ni7 cuboctahedra. In the third Ni site, Ni(2) is bonded to four equivalent Sm(2), two equivalent Ni(4), two equivalent Ni(5), and four equivalent Ni(2) atoms to form NiSm4Ni8 cuboctahedra that share corners with four equivalent Ni(2)Sm4Ni8 cuboctahedra, corners with twelve equivalent Ni(3)Sm5Ni7 cuboctahedra, edges with two equivalent Ni(2)Sm4Ni8 cuboctahedra, edges with eight equivalent Ni(3)Sm5Ni7 cuboctahedra, faces with two equivalent Ni(3)Sm5Ni7 cuboctahedra, and faces with eight equivalent Ni(2)Sm4Ni8 cuboctahedra. In the fourth Ni site, Ni(3) is bonded to two equivalent Sm(2), three equivalent Sm(1), one Ni(1), one Ni(4), one Ni(5), and four equivalent Ni(3) atoms to form distorted NiSm5Ni7 cuboctahedra that share corners with two equivalent Ni(1)Sm6Ni6 cuboctahedra, corners with six equivalent Ni(2)Sm4Ni8 cuboctahedra, corners with nine equivalent Ni(3)Sm5Ni7 cuboctahedra, edges with four equivalent Ni(2)Sm4Ni8 cuboctahedra, edges with four equivalent Ni(3)Sm5Ni7 cuboctahedra,  a faceface with one Ni(2)Sm4Ni8 cuboctahedra, faces with three equivalent Ni(1)Sm6Ni6 cuboctahedra, and faces with ten equivalent Ni(3)Sm5Ni7 cuboctahedra. In the fifth Ni site, Ni(4) is bonded in a 9-coordinate geometry to three equivalent Sm(2), three equivalent Ni(2), and three equivalent Ni(3) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Sm2Ni7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.929
_cell_length_b   4.929
_cell_length_c   24.131
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   119.997
_symmetry_Int_Tables_number   1
_cell_volume   507.697
_cell_formula_units_Z   4
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  0.667  0.333  0.530  1.0
  Sm  Sm1  1  0.333  0.667  0.470  1.0
  Sm  Sm2  1  0.333  0.667  0.030  1.0
  Sm  Sm3  1  0.667  0.333  0.970  1.0
  Sm  Sm4  1  0.667  0.333  0.674  1.0
  Sm  Sm5  1  0.333  0.667  0.326  1.0
  Sm  Sm6  1  0.333  0.667  0.174  1.0
  Sm  Sm7  1  0.667  0.333  0.826  1.0
  Ni  Ni8  1  0.000  0.000  0.500  1.0
  Ni  Ni9  1  0.000  0.000  0.000  1.0
  Ni  Ni10  1  0.167  0.334  0.750  1.0
  Ni  Ni11  1  0.167  0.833  0.750  1.0
  Ni  Ni12  1  0.666  0.833  0.750  1.0
  Ni  Ni13  1  0.833  0.666  0.250  1.0
  Ni  Ni14  1  0.833  0.167  0.250  1.0
  Ni  Ni15  1  0.334  0.167  0.250  1.0
  Ni  Ni16  1  0.166  0.333  0.587  1.0
  Ni  Ni17  1  0.166  0.834  0.587  1.0
  Ni  Ni18  1  0.667  0.834  0.587  1.0
  Ni  Ni19  1  0.834  0.667  0.413  1.0
  Ni  Ni20  1  0.834  0.166  0.413  1.0
  Ni  Ni21  1  0.333  0.166  0.413  1.0
  Ni  Ni22  1  0.834  0.667  0.087  1.0
  Ni  Ni23  1  0.834  0.166  0.087  1.0
  Ni  Ni24  1  0.333  0.166  0.087  1.0
  Ni  Ni25  1  0.166  0.333  0.913  1.0
  Ni  Ni26  1  0.166  0.834  0.913  1.0
  Ni  Ni27  1  0.667  0.834  0.913  1.0
  Ni  Ni28  1  0.000  1.000  0.669  1.0
  Ni  Ni29  1  1.000  0.000  0.331  1.0
  Ni  Ni30  1  1.000  0.000  0.169  1.0
  Ni  Ni31  1  0.000  1.000  0.831  1.0
  Ni  Ni32  1  0.667  0.333  0.332  1.0
  Ni  Ni33  1  0.333  0.667  0.668  1.0
  Ni  Ni34  1  0.333  0.667  0.832  1.0
  Ni  Ni35  1  0.667  0.333  0.168  1.0
[/CIF]
.