The structure described by Mg41Sm5 crystallizes in the tetragonal I4/m space group. There are eight inequivalent Mg sites. In the first Mg site, Mg(7) is bonded in a 12-coordinate geometry to one Mg(1), one Mg(2), one Mg(4), one Mg(5), one Mg(8), two equivalent Mg(6), two equivalent Mg(7), one Sm(1), and two equivalent Sm(2) atoms. In the second Mg site, Mg(1) is bonded in a body-centered cubic geometry to eight equivalent Mg(7) atoms. In the third Mg site, Mg(2) is bonded to two equivalent Mg(4), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), two equivalent Mg(8), and two equivalent Sm(2) atoms to form a mixture of face and corner-sharing MgSm2Mg10 cuboctahedra. In the fourth Mg site, Mg(8) is bonded in a 12-coordinate geometry to one Mg(2), one Mg(4), one Mg(5), one Mg(7), two equivalent Mg(3), two equivalent Mg(6), two equivalent Mg(8), and two equivalent Sm(2) atoms. In the fifth Mg site, Mg(3) is bonded in a 10-coordinate geometry to one Mg(3), one Mg(4), one Mg(5), two equivalent Mg(6), four equivalent Mg(8), and one Sm(2) atom. In the sixth Mg site, Mg(4) is bonded in a 14-coordinate geometry to one Mg(3), one Mg(5), two equivalent Mg(2), two equivalent Mg(7), two equivalent Mg(8), four equivalent Mg(6), one Sm(1), and one Sm(2) atom. In the seventh Mg site, Mg(5) is bonded to one Mg(3), one Mg(4), two equivalent Mg(2), two equivalent Mg(6), two equivalent Mg(7), two equivalent Mg(8), and two equivalent Sm(2) atoms to form a mixture of distorted face and corner-sharing MgSm2Mg10 cuboctahedra. In the eighth Mg site, Mg(6) is bonded in a 12-coordinate geometry to one Mg(2), one Mg(3), one Mg(5), one Mg(6), two equivalent Mg(4), two equivalent Mg(7), two equivalent Mg(8), one Sm(1), and one Sm(2) atom. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 20-coordinate geometry to four equivalent Mg(4), eight equivalent Mg(6), and eight equivalent Mg(7) atoms. In the second Sm site, Sm(2) is bonded in a 16-coordinate geometry to one Mg(3), one Mg(4), two equivalent Mg(2), two equivalent Mg(5), two equivalent Mg(6), four equivalent Mg(7), and four equivalent Mg(8) atoms. is represented by the CIF file [CIF]
data_Sm5Mg41
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.592
_cell_length_b   11.592
_cell_length_c   11.592
_cell_angle_alpha   101.501
_cell_angle_beta   101.501
_cell_angle_gamma   126.959
_symmetry_Int_Tables_number   1
_cell_volume   1113.688
_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  0.000  0.000  0.000  1.0
  Sm  Sm1  1  0.764  0.429  0.193  1.0
  Sm  Sm2  1  0.236  0.571  0.807  1.0
  Sm  Sm3  1  0.429  0.236  0.665  1.0
  Sm  Sm4  1  0.571  0.764  0.335  1.0
  Mg  Mg5  1  0.500  0.500  0.000  1.0
  Mg  Mg6  1  0.500  0.000  0.000  1.0
  Mg  Mg7  1  0.000  0.500  0.000  1.0
  Mg  Mg8  1  0.000  0.000  0.500  1.0
  Mg  Mg9  1  0.500  0.500  0.500  1.0
  Mg  Mg10  1  0.010  0.403  0.412  1.0
  Mg  Mg11  1  0.990  0.597  0.588  1.0
  Mg  Mg12  1  0.403  0.990  0.393  1.0
  Mg  Mg13  1  0.597  0.010  0.607  1.0
  Mg  Mg14  1  0.878  0.222  0.100  1.0
  Mg  Mg15  1  0.122  0.778  0.900  1.0
  Mg  Mg16  1  0.222  0.122  0.344  1.0
  Mg  Mg17  1  0.778  0.878  0.656  1.0
  Mg  Mg18  1  0.659  0.217  0.876  1.0
  Mg  Mg19  1  0.341  0.783  0.124  1.0
  Mg  Mg20  1  0.217  0.341  0.559  1.0
  Mg  Mg21  1  0.783  0.659  0.441  1.0
  Mg  Mg22  1  0.626  0.914  0.834  1.0
  Mg  Mg23  1  0.079  0.792  0.166  1.0
  Mg  Mg24  1  0.914  0.079  0.288  1.0
  Mg  Mg25  1  0.792  0.626  0.712  1.0
  Mg  Mg26  1  0.374  0.086  0.166  1.0
  Mg  Mg27  1  0.921  0.208  0.834  1.0
  Mg  Mg28  1  0.086  0.921  0.712  1.0
  Mg  Mg29  1  0.208  0.374  0.288  1.0
  Mg  Mg30  1  0.387  0.174  0.941  1.0
  Mg  Mg31  1  0.233  0.447  0.059  1.0
  Mg  Mg32  1  0.174  0.233  0.787  1.0
  Mg  Mg33  1  0.447  0.387  0.213  1.0
  Mg  Mg34  1  0.613  0.826  0.059  1.0
  Mg  Mg35  1  0.767  0.553  0.941  1.0
  Mg  Mg36  1  0.826  0.767  0.213  1.0
  Mg  Mg37  1  0.553  0.613  0.787  1.0
  Mg  Mg38  1  0.665  0.108  0.290  1.0
  Mg  Mg39  1  0.818  0.375  0.710  1.0
  Mg  Mg40  1  0.108  0.818  0.444  1.0
  Mg  Mg41  1  0.375  0.665  0.556  1.0
  Mg  Mg42  1  0.335  0.892  0.710  1.0
  Mg  Mg43  1  0.182  0.625  0.290  1.0
  Mg  Mg44  1  0.892  0.182  0.556  1.0
  Mg  Mg45  1  0.625  0.335  0.444  1.0
[/CIF]
.
The structure described by Mg41Sm5 crystallizes in the tetragonal I4/m space group. There are eight inequivalent Mg sites. In the first Mg site, Mg(7) is bonded in a 12-coordinate geometry to one Mg(1), one Mg(2), one Mg(4), one Mg(5), one Mg(8), two equivalent Mg(6), two equivalent Mg(7), one Sm(1), and two equivalent Sm(2) atoms. In the second Mg site, Mg(1) is bonded in a body-centered cubic geometry to eight equivalent Mg(7) atoms. In the third Mg site, Mg(2) is bonded to two equivalent Mg(4), two equivalent Mg(5), two equivalent Mg(6), two equivalent Mg(7), two equivalent Mg(8), and two equivalent Sm(2) atoms to form a mixture of face and corner-sharing MgSm2Mg10 cuboctahedra. In the fourth Mg site, Mg(8) is bonded in a 12-coordinate geometry to one Mg(2), one Mg(4), one Mg(5), one Mg(7), two equivalent Mg(3), two equivalent Mg(6), two equivalent Mg(8), and two equivalent Sm(2) atoms. In the fifth Mg site, Mg(3) is bonded in a 10-coordinate geometry to one Mg(3), one Mg(4), one Mg(5), two equivalent Mg(6), four equivalent Mg(8), and one Sm(2) atom. In the sixth Mg site, Mg(4) is bonded in a 14-coordinate geometry to one Mg(3), one Mg(5), two equivalent Mg(2), two equivalent Mg(7), two equivalent Mg(8), four equivalent Mg(6), one Sm(1), and one Sm(2) atom. In the seventh Mg site, Mg(5) is bonded to one Mg(3), one Mg(4), two equivalent Mg(2), two equivalent Mg(6), two equivalent Mg(7), two equivalent Mg(8), and two equivalent Sm(2) atoms to form a mixture of distorted face and corner-sharing MgSm2Mg10 cuboctahedra. In the eighth Mg site, Mg(6) is bonded in a 12-coordinate geometry to one Mg(2), one Mg(3), one Mg(5), one Mg(6), two equivalent Mg(4), two equivalent Mg(7), two equivalent Mg(8), one Sm(1), and one Sm(2) atom. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 20-coordinate geometry to four equivalent Mg(4), eight equivalent Mg(6), and eight equivalent Mg(7) atoms. In the second Sm site, Sm(2) is bonded in a 16-coordinate geometry to one Mg(3), one Mg(4), two equivalent Mg(2), two equivalent Mg(5), two equivalent Mg(6), four equivalent Mg(7), and four equivalent Mg(8) atoms. is represented by the CIF file [CIF]
data_Sm5Mg41
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.592
_cell_length_b   11.592
_cell_length_c   11.592
_cell_angle_alpha   101.501
_cell_angle_beta   101.501
_cell_angle_gamma   126.959
_symmetry_Int_Tables_number   1
_cell_volume   1113.688
_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  0.000  0.000  0.000  1.0
  Sm  Sm1  1  0.764  0.429  0.193  1.0
  Sm  Sm2  1  0.236  0.571  0.807  1.0
  Sm  Sm3  1  0.429  0.236  0.665  1.0
  Sm  Sm4  1  0.571  0.764  0.335  1.0
  Mg  Mg5  1  0.500  0.500  0.000  1.0
  Mg  Mg6  1  0.500  0.000  0.000  1.0
  Mg  Mg7  1  0.000  0.500  0.000  1.0
  Mg  Mg8  1  0.000  0.000  0.500  1.0
  Mg  Mg9  1  0.500  0.500  0.500  1.0
  Mg  Mg10  1  0.010  0.403  0.412  1.0
  Mg  Mg11  1  0.990  0.597  0.588  1.0
  Mg  Mg12  1  0.403  0.990  0.393  1.0
  Mg  Mg13  1  0.597  0.010  0.607  1.0
  Mg  Mg14  1  0.878  0.222  0.100  1.0
  Mg  Mg15  1  0.122  0.778  0.900  1.0
  Mg  Mg16  1  0.222  0.122  0.344  1.0
  Mg  Mg17  1  0.778  0.878  0.656  1.0
  Mg  Mg18  1  0.659  0.217  0.876  1.0
  Mg  Mg19  1  0.341  0.783  0.124  1.0
  Mg  Mg20  1  0.217  0.341  0.559  1.0
  Mg  Mg21  1  0.783  0.659  0.441  1.0
  Mg  Mg22  1  0.626  0.914  0.834  1.0
  Mg  Mg23  1  0.079  0.792  0.166  1.0
  Mg  Mg24  1  0.914  0.079  0.288  1.0
  Mg  Mg25  1  0.792  0.626  0.712  1.0
  Mg  Mg26  1  0.374  0.086  0.166  1.0
  Mg  Mg27  1  0.921  0.208  0.834  1.0
  Mg  Mg28  1  0.086  0.921  0.712  1.0
  Mg  Mg29  1  0.208  0.374  0.288  1.0
  Mg  Mg30  1  0.387  0.174  0.941  1.0
  Mg  Mg31  1  0.233  0.447  0.059  1.0
  Mg  Mg32  1  0.174  0.233  0.787  1.0
  Mg  Mg33  1  0.447  0.387  0.213  1.0
  Mg  Mg34  1  0.613  0.826  0.059  1.0
  Mg  Mg35  1  0.767  0.553  0.941  1.0
  Mg  Mg36  1  0.826  0.767  0.213  1.0
  Mg  Mg37  1  0.553  0.613  0.787  1.0
  Mg  Mg38  1  0.665  0.108  0.290  1.0
  Mg  Mg39  1  0.818  0.375  0.710  1.0
  Mg  Mg40  1  0.108  0.818  0.444  1.0
  Mg  Mg41  1  0.375  0.665  0.556  1.0
  Mg  Mg42  1  0.335  0.892  0.710  1.0
  Mg  Mg43  1  0.182  0.625  0.290  1.0
  Mg  Mg44  1  0.892  0.182  0.556  1.0
  Mg  Mg45  1  0.625  0.335  0.444  1.0
[/CIF]
.