The material structure described by Mg3SmNi8 is Hexagonal Laves-derived structured and crystallizes in the monoclinic Cm space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 16-coordinate geometry to one Mg(3), three equivalent Mg(2), one Ni(3), two equivalent Ni(1), two equivalent Ni(4), three equivalent Ni(5), and four equivalent Ni(2) atoms. In the second Mg site, Mg(2) is bonded in a 16-coordinate geometry to three equivalent Mg(1), one Sm(1), one Ni(4), two equivalent Ni(2), two equivalent Ni(3), three equivalent Ni(5), and four equivalent Ni(1) atoms. In the third Mg site, Mg(3) is bonded in a 16-coordinate geometry to one Mg(1), three equivalent Sm(1), one Ni(3), two equivalent Ni(1), two equivalent Ni(4), three equivalent Ni(6), and four equivalent Ni(2) atoms. Sm(1) is bonded in a 16-coordinate geometry to one Mg(2), three equivalent Mg(3), one Ni(4), two equivalent Ni(2), two equivalent Ni(3), three equivalent Ni(6), and four equivalent Ni(1) atoms. There are six inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one Mg(1), one Mg(3), two equivalent Mg(2), two equivalent Sm(1), one Ni(5), one Ni(6), two equivalent Ni(1), and two equivalent Ni(3) atoms to form NiSm2Mg4Ni6 cuboctahedra that share corners with two equivalent Ni(5)Mg6Ni6 cuboctahedra, corners with two equivalent Ni(6)Sm3Mg3Ni6 cuboctahedra, corners with four equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, corners with four equivalent Ni(4)SmMg5Ni6 cuboctahedra, corners with six equivalent Ni(2)SmMg5Ni6 cuboctahedra, edges with two equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, edges with four equivalent Ni(2)SmMg5Ni6 cuboctahedra, faces with two equivalent Ni(2)SmMg5Ni6 cuboctahedra, faces with two equivalent Ni(4)SmMg5Ni6 cuboctahedra, faces with three equivalent Ni(5)Mg6Ni6 cuboctahedra, faces with three equivalent Ni(6)Sm3Mg3Ni6 cuboctahedra, faces with four equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, and faces with four equivalent Ni(3)Sm2Mg4Ni6 cuboctahedra. In the second Ni site, Ni(2) is bonded to one Mg(2), two equivalent Mg(1), two equivalent Mg(3), one Sm(1), one Ni(5), one Ni(6), two equivalent Ni(2), and two equivalent Ni(4) atoms to form NiSmMg5Ni6 cuboctahedra that share corners with two equivalent Ni(5)Mg6Ni6 cuboctahedra, corners with two equivalent Ni(6)Sm3Mg3Ni6 cuboctahedra, corners with four equivalent Ni(3)Sm2Mg4Ni6 cuboctahedra, corners with four equivalent Ni(2)SmMg5Ni6 cuboctahedra, corners with six equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, edges with two equivalent Ni(2)SmMg5Ni6 cuboctahedra, edges with four equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, faces with two equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, faces with two equivalent Ni(3)Sm2Mg4Ni6 cuboctahedra, faces with three equivalent Ni(5)Mg6Ni6 cuboctahedra, faces with three equivalent Ni(6)Sm3Mg3Ni6 cuboctahedra, faces with four equivalent Ni(2)SmMg5Ni6 cuboctahedra, and faces with four equivalent Ni(4)SmMg5Ni6 cuboctahedra. In the third Ni site, Ni(3) is bonded to one Mg(1), one Mg(3), two equivalent Mg(2), two equivalent Sm(1), one Ni(5), one Ni(6), and four equivalent Ni(1) atoms to form NiSm2Mg4Ni6 cuboctahedra that share corners with two equivalent Ni(5)Mg6Ni6 cuboctahedra, corners with two equivalent Ni(6)Sm3Mg3Ni6 cuboctahedra, corners with two equivalent Ni(4)SmMg5Ni6 cuboctahedra, corners with four equivalent Ni(3)Sm2Mg4Ni6 cuboctahedra, corners with eight equivalent Ni(2)SmMg5Ni6 cuboctahedra, edges with two equivalent Ni(3)Sm2Mg4Ni6 cuboctahedra, edges with four equivalent Ni(4)SmMg5Ni6 cuboctahedra, faces with three equivalent Ni(5)Mg6Ni6 cuboctahedra, faces with three equivalent Ni(6)Sm3Mg3Ni6 cuboctahedra, faces with four equivalent Ni(2)SmMg5Ni6 cuboctahedra, and faces with eight equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra. In the fourth Ni site, Ni(4) is bonded to one Mg(2), two equivalent Mg(1), two equivalent Mg(3), one Sm(1), one Ni(5), one Ni(6), and four equivalent Ni(2) atoms to form NiSmMg5Ni6 cuboctahedra that share corners with two equivalent Ni(5)Mg6Ni6 cuboctahedra, corners with two equivalent Ni(3)Sm2Mg4Ni6 cuboctahedra, corners with two equivalent Ni(6)Sm3Mg3Ni6 cuboctahedra, corners with four equivalent Ni(4)SmMg5Ni6 cuboctahedra, corners with eight equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, edges with two equivalent Ni(4)SmMg5Ni6 cuboctahedra, edges with four equivalent Ni(3)Sm2Mg4Ni6 cuboctahedra, faces with three equivalent Ni(5)Mg6Ni6 cuboctahedra, faces with three equivalent Ni(6)Sm3Mg3Ni6 cuboctahedra, faces with four equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, and faces with eight equivalent Ni(2)SmMg5Ni6 cuboctahedra. In the fifth Ni site, Ni(5) is bonded to three equivalent Mg(1), three equivalent Mg(2), one Ni(3), one Ni(4), two equivalent Ni(1), and two equivalent Ni(2) atoms to form NiMg6Ni6 cuboctahedra that share corners with two equivalent Ni(3)Sm2Mg4Ni6 cuboctahedra, corners with two equivalent Ni(4)SmMg5Ni6 cuboctahedra, corners with four equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, corners with four equivalent Ni(2)SmMg5Ni6 cuboctahedra, corners with six equivalent Ni(6)Sm3Mg3Ni6 cuboctahedra, edges with six equivalent Ni(5)Mg6Ni6 cuboctahedra, faces with three equivalent Ni(3)Sm2Mg4Ni6 cuboctahedra, faces with three equivalent Ni(4)SmMg5Ni6 cuboctahedra, faces with six equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, and faces with six equivalent Ni(2)SmMg5Ni6 cuboctahedra. In the sixth Ni site, Ni(6) is bonded to three equivalent Mg(3), three equivalent Sm(1), one Ni(3), one Ni(4), two equivalent Ni(1), and two equivalent Ni(2) atoms to form NiSm3Mg3Ni6 cuboctahedra that share corners with two equivalent Ni(3)Sm2Mg4Ni6 cuboctahedra, corners with two equivalent Ni(4)SmMg5Ni6 cuboctahedra, corners with four equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, corners with four equivalent Ni(2)SmMg5Ni6 cuboctahedra, corners with six equivalent Ni(5)Mg6Ni6 cuboctahedra, edges with six equivalent Ni(6)Sm3Mg3Ni6 cuboctahedra, faces with three equivalent Ni(3)Sm2Mg4Ni6 cuboctahedra, faces with three equivalent Ni(4)SmMg5Ni6 cuboctahedra, faces with six equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, and faces with six equivalent Ni(2)SmMg5Ni6 cuboctahedra. is represented by the CIF card [CIF]
data_SmMg3Ni8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.844
_cell_length_b   4.844
_cell_length_c   8.463
_cell_angle_alpha   73.377
_cell_angle_beta   90.009
_cell_angle_gamma   119.996
_symmetry_Int_Tables_number   1
_cell_volume   162.347
_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
  Sm  Sm0  1  0.999  0.999  0.003  1.0
  Mg  Mg1  1  0.501  0.002  0.495  1.0
  Mg  Mg2  1  0.870  0.741  0.388  1.0
  Mg  Mg3  1  0.383  0.766  0.852  1.0
  Ni  Ni4  1  0.435  0.369  0.197  1.0
  Ni  Ni5  1  0.937  0.381  0.682  1.0
  Ni  Ni6  1  0.435  0.870  0.197  1.0
  Ni  Ni7  1  0.937  0.874  0.682  1.0
  Ni  Ni8  1  0.186  0.373  0.440  1.0
  Ni  Ni9  1  0.688  0.377  0.936  1.0
  Ni  Ni10  1  0.934  0.369  0.197  1.0
  Ni  Ni11  1  0.444  0.381  0.682  1.0
[/CIF]
.
The material structure described by Mg3SmNi8 is Hexagonal Laves-derived structured and crystallizes in the monoclinic Cm space group. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 16-coordinate geometry to one Mg(3), three equivalent Mg(2), one Ni(3), two equivalent Ni(1), two equivalent Ni(4), three equivalent Ni(5), and four equivalent Ni(2) atoms. In the second Mg site, Mg(2) is bonded in a 16-coordinate geometry to three equivalent Mg(1), one Sm(1), one Ni(4), two equivalent Ni(2), two equivalent Ni(3), three equivalent Ni(5), and four equivalent Ni(1) atoms. In the third Mg site, Mg(3) is bonded in a 16-coordinate geometry to one Mg(1), three equivalent Sm(1), one Ni(3), two equivalent Ni(1), two equivalent Ni(4), three equivalent Ni(6), and four equivalent Ni(2) atoms. Sm(1) is bonded in a 16-coordinate geometry to one Mg(2), three equivalent Mg(3), one Ni(4), two equivalent Ni(2), two equivalent Ni(3), three equivalent Ni(6), and four equivalent Ni(1) atoms. There are six inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one Mg(1), one Mg(3), two equivalent Mg(2), two equivalent Sm(1), one Ni(5), one Ni(6), two equivalent Ni(1), and two equivalent Ni(3) atoms to form NiSm2Mg4Ni6 cuboctahedra that share corners with two equivalent Ni(5)Mg6Ni6 cuboctahedra, corners with two equivalent Ni(6)Sm3Mg3Ni6 cuboctahedra, corners with four equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, corners with four equivalent Ni(4)SmMg5Ni6 cuboctahedra, corners with six equivalent Ni(2)SmMg5Ni6 cuboctahedra, edges with two equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, edges with four equivalent Ni(2)SmMg5Ni6 cuboctahedra, faces with two equivalent Ni(2)SmMg5Ni6 cuboctahedra, faces with two equivalent Ni(4)SmMg5Ni6 cuboctahedra, faces with three equivalent Ni(5)Mg6Ni6 cuboctahedra, faces with three equivalent Ni(6)Sm3Mg3Ni6 cuboctahedra, faces with four equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, and faces with four equivalent Ni(3)Sm2Mg4Ni6 cuboctahedra. In the second Ni site, Ni(2) is bonded to one Mg(2), two equivalent Mg(1), two equivalent Mg(3), one Sm(1), one Ni(5), one Ni(6), two equivalent Ni(2), and two equivalent Ni(4) atoms to form NiSmMg5Ni6 cuboctahedra that share corners with two equivalent Ni(5)Mg6Ni6 cuboctahedra, corners with two equivalent Ni(6)Sm3Mg3Ni6 cuboctahedra, corners with four equivalent Ni(3)Sm2Mg4Ni6 cuboctahedra, corners with four equivalent Ni(2)SmMg5Ni6 cuboctahedra, corners with six equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, edges with two equivalent Ni(2)SmMg5Ni6 cuboctahedra, edges with four equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, faces with two equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, faces with two equivalent Ni(3)Sm2Mg4Ni6 cuboctahedra, faces with three equivalent Ni(5)Mg6Ni6 cuboctahedra, faces with three equivalent Ni(6)Sm3Mg3Ni6 cuboctahedra, faces with four equivalent Ni(2)SmMg5Ni6 cuboctahedra, and faces with four equivalent Ni(4)SmMg5Ni6 cuboctahedra. In the third Ni site, Ni(3) is bonded to one Mg(1), one Mg(3), two equivalent Mg(2), two equivalent Sm(1), one Ni(5), one Ni(6), and four equivalent Ni(1) atoms to form NiSm2Mg4Ni6 cuboctahedra that share corners with two equivalent Ni(5)Mg6Ni6 cuboctahedra, corners with two equivalent Ni(6)Sm3Mg3Ni6 cuboctahedra, corners with two equivalent Ni(4)SmMg5Ni6 cuboctahedra, corners with four equivalent Ni(3)Sm2Mg4Ni6 cuboctahedra, corners with eight equivalent Ni(2)SmMg5Ni6 cuboctahedra, edges with two equivalent Ni(3)Sm2Mg4Ni6 cuboctahedra, edges with four equivalent Ni(4)SmMg5Ni6 cuboctahedra, faces with three equivalent Ni(5)Mg6Ni6 cuboctahedra, faces with three equivalent Ni(6)Sm3Mg3Ni6 cuboctahedra, faces with four equivalent Ni(2)SmMg5Ni6 cuboctahedra, and faces with eight equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra. In the fourth Ni site, Ni(4) is bonded to one Mg(2), two equivalent Mg(1), two equivalent Mg(3), one Sm(1), one Ni(5), one Ni(6), and four equivalent Ni(2) atoms to form NiSmMg5Ni6 cuboctahedra that share corners with two equivalent Ni(5)Mg6Ni6 cuboctahedra, corners with two equivalent Ni(3)Sm2Mg4Ni6 cuboctahedra, corners with two equivalent Ni(6)Sm3Mg3Ni6 cuboctahedra, corners with four equivalent Ni(4)SmMg5Ni6 cuboctahedra, corners with eight equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, edges with two equivalent Ni(4)SmMg5Ni6 cuboctahedra, edges with four equivalent Ni(3)Sm2Mg4Ni6 cuboctahedra, faces with three equivalent Ni(5)Mg6Ni6 cuboctahedra, faces with three equivalent Ni(6)Sm3Mg3Ni6 cuboctahedra, faces with four equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, and faces with eight equivalent Ni(2)SmMg5Ni6 cuboctahedra. In the fifth Ni site, Ni(5) is bonded to three equivalent Mg(1), three equivalent Mg(2), one Ni(3), one Ni(4), two equivalent Ni(1), and two equivalent Ni(2) atoms to form NiMg6Ni6 cuboctahedra that share corners with two equivalent Ni(3)Sm2Mg4Ni6 cuboctahedra, corners with two equivalent Ni(4)SmMg5Ni6 cuboctahedra, corners with four equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, corners with four equivalent Ni(2)SmMg5Ni6 cuboctahedra, corners with six equivalent Ni(6)Sm3Mg3Ni6 cuboctahedra, edges with six equivalent Ni(5)Mg6Ni6 cuboctahedra, faces with three equivalent Ni(3)Sm2Mg4Ni6 cuboctahedra, faces with three equivalent Ni(4)SmMg5Ni6 cuboctahedra, faces with six equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, and faces with six equivalent Ni(2)SmMg5Ni6 cuboctahedra. In the sixth Ni site, Ni(6) is bonded to three equivalent Mg(3), three equivalent Sm(1), one Ni(3), one Ni(4), two equivalent Ni(1), and two equivalent Ni(2) atoms to form NiSm3Mg3Ni6 cuboctahedra that share corners with two equivalent Ni(3)Sm2Mg4Ni6 cuboctahedra, corners with two equivalent Ni(4)SmMg5Ni6 cuboctahedra, corners with four equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, corners with four equivalent Ni(2)SmMg5Ni6 cuboctahedra, corners with six equivalent Ni(5)Mg6Ni6 cuboctahedra, edges with six equivalent Ni(6)Sm3Mg3Ni6 cuboctahedra, faces with three equivalent Ni(3)Sm2Mg4Ni6 cuboctahedra, faces with three equivalent Ni(4)SmMg5Ni6 cuboctahedra, faces with six equivalent Ni(1)Sm2Mg4Ni6 cuboctahedra, and faces with six equivalent Ni(2)SmMg5Ni6 cuboctahedra. is represented by the CIF card [CIF]
data_SmMg3Ni8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.844
_cell_length_b   4.844
_cell_length_c   8.463
_cell_angle_alpha   73.377
_cell_angle_beta   90.009
_cell_angle_gamma   119.996
_symmetry_Int_Tables_number   1
_cell_volume   162.347
_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
  Sm  Sm0  1  0.999  0.999  0.003  1.0
  Mg  Mg1  1  0.501  0.002  0.495  1.0
  Mg  Mg2  1  0.870  0.741  0.388  1.0
  Mg  Mg3  1  0.383  0.766  0.852  1.0
  Ni  Ni4  1  0.435  0.369  0.197  1.0
  Ni  Ni5  1  0.937  0.381  0.682  1.0
  Ni  Ni6  1  0.435  0.870  0.197  1.0
  Ni  Ni7  1  0.937  0.874  0.682  1.0
  Ni  Ni8  1  0.186  0.373  0.440  1.0
  Ni  Ni9  1  0.688  0.377  0.936  1.0
  Ni  Ni10  1  0.934  0.369  0.197  1.0
  Ni  Ni11  1  0.444  0.381  0.682  1.0
[/CIF]
.