The structure described by MgSm3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded to four equivalent Sm(1) and eight equivalent Sm(2) atoms to form MgSm12 cuboctahedra that share corners with four equivalent Mg(1)Sm12 cuboctahedra, corners with eight equivalent Sm(1)Sm8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Sm12 cuboctahedra, edges with sixteen equivalent Sm(2)Sm8Mg4 cuboctahedra, faces with four equivalent Mg(1)Sm12 cuboctahedra, faces with six equivalent Sm(1)Sm8Mg4 cuboctahedra, and faces with eight equivalent Sm(2)Sm8Mg4 cuboctahedra. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded to four equivalent Mg(1) and eight equivalent Sm(2) atoms to form SmSm8Mg4 cuboctahedra that share corners with four equivalent Sm(1)Sm8Mg4 cuboctahedra, corners with eight equivalent Mg(1)Sm12 cuboctahedra, edges with eight equivalent Sm(1)Sm8Mg4 cuboctahedra, edges with sixteen equivalent Sm(2)Sm8Mg4 cuboctahedra, faces with four equivalent Sm(1)Sm8Mg4 cuboctahedra, faces with six equivalent Mg(1)Sm12 cuboctahedra, and faces with eight equivalent Sm(2)Sm8Mg4 cuboctahedra. In the second Sm site, Sm(2) is bonded to four equivalent Mg(1), four equivalent Sm(1), and four equivalent Sm(2) atoms to form SmSm8Mg4 cuboctahedra that share corners with twelve equivalent Sm(2)Sm8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Sm12 cuboctahedra, edges with eight equivalent Sm(1)Sm8Mg4 cuboctahedra, edges with eight equivalent Sm(2)Sm8Mg4 cuboctahedra, faces with four equivalent Mg(1)Sm12 cuboctahedra, faces with four equivalent Sm(1)Sm8Mg4 cuboctahedra, and faces with ten equivalent Sm(2)Sm8Mg4 cuboctahedra. is represented by the CIF file [CIF]
data_Sm3Mg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.093
_cell_length_b   6.093
_cell_length_c   6.093
_cell_angle_alpha   131.858
_cell_angle_beta   131.858
_cell_angle_gamma   70.453
_symmetry_Int_Tables_number   1
_cell_volume   122.947
_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  0.500  0.500  0.000  1.0
  Sm  Sm1  1  0.750  0.250  0.500  1.0
  Sm  Sm2  1  0.250  0.750  0.500  1.0
  Mg  Mg3  1  0.000  0.000  0.000  1.0
[/CIF]
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The structure described by MgSm3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded to four equivalent Sm(1) and eight equivalent Sm(2) atoms to form MgSm12 cuboctahedra that share corners with four equivalent Mg(1)Sm12 cuboctahedra, corners with eight equivalent Sm(1)Sm8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Sm12 cuboctahedra, edges with sixteen equivalent Sm(2)Sm8Mg4 cuboctahedra, faces with four equivalent Mg(1)Sm12 cuboctahedra, faces with six equivalent Sm(1)Sm8Mg4 cuboctahedra, and faces with eight equivalent Sm(2)Sm8Mg4 cuboctahedra. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded to four equivalent Mg(1) and eight equivalent Sm(2) atoms to form SmSm8Mg4 cuboctahedra that share corners with four equivalent Sm(1)Sm8Mg4 cuboctahedra, corners with eight equivalent Mg(1)Sm12 cuboctahedra, edges with eight equivalent Sm(1)Sm8Mg4 cuboctahedra, edges with sixteen equivalent Sm(2)Sm8Mg4 cuboctahedra, faces with four equivalent Sm(1)Sm8Mg4 cuboctahedra, faces with six equivalent Mg(1)Sm12 cuboctahedra, and faces with eight equivalent Sm(2)Sm8Mg4 cuboctahedra. In the second Sm site, Sm(2) is bonded to four equivalent Mg(1), four equivalent Sm(1), and four equivalent Sm(2) atoms to form SmSm8Mg4 cuboctahedra that share corners with twelve equivalent Sm(2)Sm8Mg4 cuboctahedra, edges with eight equivalent Mg(1)Sm12 cuboctahedra, edges with eight equivalent Sm(1)Sm8Mg4 cuboctahedra, edges with eight equivalent Sm(2)Sm8Mg4 cuboctahedra, faces with four equivalent Mg(1)Sm12 cuboctahedra, faces with four equivalent Sm(1)Sm8Mg4 cuboctahedra, and faces with ten equivalent Sm(2)Sm8Mg4 cuboctahedra. is represented by the CIF file [CIF]
data_Sm3Mg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.093
_cell_length_b   6.093
_cell_length_c   6.093
_cell_angle_alpha   131.858
_cell_angle_beta   131.858
_cell_angle_gamma   70.453
_symmetry_Int_Tables_number   1
_cell_volume   122.947
_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  0.500  0.500  0.000  1.0
  Sm  Sm1  1  0.750  0.250  0.500  1.0
  Sm  Sm2  1  0.250  0.750  0.500  1.0
  Mg  Mg3  1  0.000  0.000  0.000  1.0
[/CIF]
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