The compound described by Al18Mg3Mn2 crystallizes in the cubic Fd-3m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 16-coordinate geometry to four equivalent Mg(2) and twelve equivalent Al(1) atoms. In the second Mg site, Mg(2) is bonded in a 14-coordinate geometry to two equivalent Mg(1) and twelve equivalent Al(1) atoms. Mn(1) is bonded to six equivalent Al(1) and six equivalent Al(2) atoms to form MnAl12 cuboctahedra that share corners with six equivalent Mn(1)Al12 cuboctahedra, edges with eighteen equivalent Al(1)Mg3MnAl8 cuboctahedra, and faces with six equivalent Al(1)Mg3MnAl8 cuboctahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one Mg(1), two equivalent Mg(2), one Mn(1), three equivalent Al(2), and five equivalent Al(1) atoms to form AlMg3MnAl8 cuboctahedra that share corners with fifteen equivalent Al(1)Mg3MnAl8 cuboctahedra, edges with two equivalent Al(1)Mg3MnAl8 cuboctahedra, edges with three equivalent Mn(1)Al12 cuboctahedra,  a faceface with one Mn(1)Al12 cuboctahedra, and faces with fifteen equivalent Al(1)Mg3MnAl8 cuboctahedra. In the second Al site, Al(2) is bonded in a 12-coordinate geometry to two equivalent Mn(1), four equivalent Al(2), and six equivalent Al(1) atoms. is represented by the CIF card [CIF]
data_Mg3(MnAl9)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.196
_cell_length_b   10.196
_cell_length_c   10.196
_cell_angle_alpha   60.000
_cell_angle_beta   60.000
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   749.429
_cell_formula_units_Z   2
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
  Mg  Mg0  1  0.250  0.250  0.250  1.0
  Mg  Mg1  1  0.625  0.125  0.125  1.0
  Mg  Mg2  1  0.125  0.625  0.125  1.0
  Mg  Mg3  1  0.000  0.000  0.000  1.0
  Mg  Mg4  1  0.125  0.125  0.125  1.0
  Mg  Mg5  1  0.125  0.125  0.625  1.0
  Mn  Mn6  1  0.625  0.625  0.125  1.0
  Mn  Mn7  1  0.625  0.625  0.625  1.0
  Mn  Mn8  1  0.625  0.125  0.625  1.0
  Mn  Mn9  1  0.125  0.625  0.625  1.0
  Al  Al10  1  0.335  0.066  0.799  1.0
  Al  Al11  1  0.066  0.799  0.335  1.0
  Al  Al12  1  0.915  0.184  0.451  1.0
  Al  Al13  1  0.184  0.451  0.451  1.0
  Al  Al14  1  0.066  0.335  0.799  1.0
  Al  Al15  1  0.799  0.799  0.066  1.0
  Al  Al16  1  0.799  0.066  0.799  1.0
  Al  Al17  1  0.637  0.637  0.363  1.0
  Al  Al18  1  0.799  0.335  0.066  1.0
  Al  Al19  1  0.451  0.451  0.184  1.0
  Al  Al20  1  0.451  0.915  0.451  1.0
  Al  Al21  1  0.799  0.066  0.335  1.0
  Al  Al22  1  0.637  0.363  0.637  1.0
  Al  Al23  1  0.451  0.184  0.915  1.0
  Al  Al24  1  0.184  0.915  0.451  1.0
  Al  Al25  1  0.887  0.887  0.613  1.0
  Al  Al26  1  0.066  0.799  0.799  1.0
  Al  Al27  1  0.335  0.799  0.066  1.0
  Al  Al28  1  0.799  0.335  0.799  1.0
  Al  Al29  1  0.915  0.451  0.184  1.0
  Al  Al30  1  0.613  0.887  0.887  1.0
  Al  Al31  1  0.637  0.363  0.363  1.0
  Al  Al32  1  0.451  0.184  0.451  1.0
  Al  Al33  1  0.613  0.887  0.613  1.0
  Al  Al34  1  0.184  0.451  0.915  1.0
  Al  Al35  1  0.915  0.451  0.451  1.0
  Al  Al36  1  0.363  0.637  0.637  1.0
  Al  Al37  1  0.613  0.613  0.887  1.0
  Al  Al38  1  0.887  0.613  0.613  1.0
  Al  Al39  1  0.363  0.363  0.637  1.0
  Al  Al40  1  0.451  0.451  0.915  1.0
  Al  Al41  1  0.799  0.799  0.335  1.0
  Al  Al42  1  0.335  0.799  0.799  1.0
  Al  Al43  1  0.363  0.637  0.363  1.0
  Al  Al44  1  0.887  0.613  0.887  1.0
  Al  Al45  1  0.451  0.915  0.184  1.0
[/CIF]
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The compound described by Al18Mg3Mn2 crystallizes in the cubic Fd-3m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 16-coordinate geometry to four equivalent Mg(2) and twelve equivalent Al(1) atoms. In the second Mg site, Mg(2) is bonded in a 14-coordinate geometry to two equivalent Mg(1) and twelve equivalent Al(1) atoms. Mn(1) is bonded to six equivalent Al(1) and six equivalent Al(2) atoms to form MnAl12 cuboctahedra that share corners with six equivalent Mn(1)Al12 cuboctahedra, edges with eighteen equivalent Al(1)Mg3MnAl8 cuboctahedra, and faces with six equivalent Al(1)Mg3MnAl8 cuboctahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one Mg(1), two equivalent Mg(2), one Mn(1), three equivalent Al(2), and five equivalent Al(1) atoms to form AlMg3MnAl8 cuboctahedra that share corners with fifteen equivalent Al(1)Mg3MnAl8 cuboctahedra, edges with two equivalent Al(1)Mg3MnAl8 cuboctahedra, edges with three equivalent Mn(1)Al12 cuboctahedra,  a faceface with one Mn(1)Al12 cuboctahedra, and faces with fifteen equivalent Al(1)Mg3MnAl8 cuboctahedra. In the second Al site, Al(2) is bonded in a 12-coordinate geometry to two equivalent Mn(1), four equivalent Al(2), and six equivalent Al(1) atoms. is represented by the CIF card [CIF]
data_Mg3(MnAl9)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.196
_cell_length_b   10.196
_cell_length_c   10.196
_cell_angle_alpha   60.000
_cell_angle_beta   60.000
_cell_angle_gamma   60.000
_symmetry_Int_Tables_number   1
_cell_volume   749.429
_cell_formula_units_Z   2
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
  Mg  Mg0  1  0.250  0.250  0.250  1.0
  Mg  Mg1  1  0.625  0.125  0.125  1.0
  Mg  Mg2  1  0.125  0.625  0.125  1.0
  Mg  Mg3  1  0.000  0.000  0.000  1.0
  Mg  Mg4  1  0.125  0.125  0.125  1.0
  Mg  Mg5  1  0.125  0.125  0.625  1.0
  Mn  Mn6  1  0.625  0.625  0.125  1.0
  Mn  Mn7  1  0.625  0.625  0.625  1.0
  Mn  Mn8  1  0.625  0.125  0.625  1.0
  Mn  Mn9  1  0.125  0.625  0.625  1.0
  Al  Al10  1  0.335  0.066  0.799  1.0
  Al  Al11  1  0.066  0.799  0.335  1.0
  Al  Al12  1  0.915  0.184  0.451  1.0
  Al  Al13  1  0.184  0.451  0.451  1.0
  Al  Al14  1  0.066  0.335  0.799  1.0
  Al  Al15  1  0.799  0.799  0.066  1.0
  Al  Al16  1  0.799  0.066  0.799  1.0
  Al  Al17  1  0.637  0.637  0.363  1.0
  Al  Al18  1  0.799  0.335  0.066  1.0
  Al  Al19  1  0.451  0.451  0.184  1.0
  Al  Al20  1  0.451  0.915  0.451  1.0
  Al  Al21  1  0.799  0.066  0.335  1.0
  Al  Al22  1  0.637  0.363  0.637  1.0
  Al  Al23  1  0.451  0.184  0.915  1.0
  Al  Al24  1  0.184  0.915  0.451  1.0
  Al  Al25  1  0.887  0.887  0.613  1.0
  Al  Al26  1  0.066  0.799  0.799  1.0
  Al  Al27  1  0.335  0.799  0.066  1.0
  Al  Al28  1  0.799  0.335  0.799  1.0
  Al  Al29  1  0.915  0.451  0.184  1.0
  Al  Al30  1  0.613  0.887  0.887  1.0
  Al  Al31  1  0.637  0.363  0.363  1.0
  Al  Al32  1  0.451  0.184  0.451  1.0
  Al  Al33  1  0.613  0.887  0.613  1.0
  Al  Al34  1  0.184  0.451  0.915  1.0
  Al  Al35  1  0.915  0.451  0.451  1.0
  Al  Al36  1  0.363  0.637  0.637  1.0
  Al  Al37  1  0.613  0.613  0.887  1.0
  Al  Al38  1  0.887  0.613  0.613  1.0
  Al  Al39  1  0.363  0.363  0.637  1.0
  Al  Al40  1  0.451  0.451  0.915  1.0
  Al  Al41  1  0.799  0.799  0.335  1.0
  Al  Al42  1  0.335  0.799  0.799  1.0
  Al  Al43  1  0.363  0.637  0.363  1.0
  Al  Al44  1  0.887  0.613  0.887  1.0
  Al  Al45  1  0.451  0.915  0.184  1.0
[/CIF]
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