The material structure described by Al3Mg is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded to four equivalent Al(1) and eight equivalent Al(2) atoms to form MgAl12 cuboctahedra that share corners with four equivalent Mg(1)Al12 cuboctahedra, corners with eight equivalent Al(1)Mg4Al8 cuboctahedra, edges with eight equivalent Mg(1)Al12 cuboctahedra, edges with sixteen equivalent Al(2)Mg4Al8 cuboctahedra, faces with four equivalent Mg(1)Al12 cuboctahedra, faces with six equivalent Al(1)Mg4Al8 cuboctahedra, and faces with eight equivalent Al(2)Mg4Al8 cuboctahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent Mg(1) and eight equivalent Al(2) atoms to form AlMg4Al8 cuboctahedra that share corners with four equivalent Al(1)Mg4Al8 cuboctahedra, corners with eight equivalent Mg(1)Al12 cuboctahedra, edges with eight equivalent Al(1)Mg4Al8 cuboctahedra, edges with sixteen equivalent Al(2)Mg4Al8 cuboctahedra, faces with four equivalent Al(1)Mg4Al8 cuboctahedra, faces with six equivalent Mg(1)Al12 cuboctahedra, and faces with eight equivalent Al(2)Mg4Al8 cuboctahedra. In the second Al site, Al(2) is bonded to four equivalent Mg(1), four equivalent Al(1), and four equivalent Al(2) atoms to form AlMg4Al8 cuboctahedra that share corners with twelve equivalent Al(2)Mg4Al8 cuboctahedra, edges with eight equivalent Mg(1)Al12 cuboctahedra, edges with eight equivalent Al(1)Mg4Al8 cuboctahedra, edges with eight equivalent Al(2)Mg4Al8 cuboctahedra, faces with four equivalent Mg(1)Al12 cuboctahedra, faces with four equivalent Al(1)Mg4Al8 cuboctahedra, and faces with ten equivalent Al(2)Mg4Al8 cuboctahedra. is represented by the CIF card [CIF]
data_MgAl3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.034
_cell_length_b   5.034
_cell_length_c   5.034
_cell_angle_alpha   132.055
_cell_angle_beta   132.055
_cell_angle_gamma   70.142
_symmetry_Int_Tables_number   1
_cell_volume   68.958
_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
  Mg  Mg0  1  0.000  0.000  0.000  1.0
  Al  Al1  1  0.500  0.500  0.000  1.0
  Al  Al2  1  0.250  0.750  0.500  1.0
  Al  Al3  1  0.750  0.250  0.500  1.0
[/CIF]
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The material structure described by Al3Mg is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. Mg(1) is bonded to four equivalent Al(1) and eight equivalent Al(2) atoms to form MgAl12 cuboctahedra that share corners with four equivalent Mg(1)Al12 cuboctahedra, corners with eight equivalent Al(1)Mg4Al8 cuboctahedra, edges with eight equivalent Mg(1)Al12 cuboctahedra, edges with sixteen equivalent Al(2)Mg4Al8 cuboctahedra, faces with four equivalent Mg(1)Al12 cuboctahedra, faces with six equivalent Al(1)Mg4Al8 cuboctahedra, and faces with eight equivalent Al(2)Mg4Al8 cuboctahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent Mg(1) and eight equivalent Al(2) atoms to form AlMg4Al8 cuboctahedra that share corners with four equivalent Al(1)Mg4Al8 cuboctahedra, corners with eight equivalent Mg(1)Al12 cuboctahedra, edges with eight equivalent Al(1)Mg4Al8 cuboctahedra, edges with sixteen equivalent Al(2)Mg4Al8 cuboctahedra, faces with four equivalent Al(1)Mg4Al8 cuboctahedra, faces with six equivalent Mg(1)Al12 cuboctahedra, and faces with eight equivalent Al(2)Mg4Al8 cuboctahedra. In the second Al site, Al(2) is bonded to four equivalent Mg(1), four equivalent Al(1), and four equivalent Al(2) atoms to form AlMg4Al8 cuboctahedra that share corners with twelve equivalent Al(2)Mg4Al8 cuboctahedra, edges with eight equivalent Mg(1)Al12 cuboctahedra, edges with eight equivalent Al(1)Mg4Al8 cuboctahedra, edges with eight equivalent Al(2)Mg4Al8 cuboctahedra, faces with four equivalent Mg(1)Al12 cuboctahedra, faces with four equivalent Al(1)Mg4Al8 cuboctahedra, and faces with ten equivalent Al(2)Mg4Al8 cuboctahedra. is represented by the CIF card [CIF]
data_MgAl3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.034
_cell_length_b   5.034
_cell_length_c   5.034
_cell_angle_alpha   132.055
_cell_angle_beta   132.055
_cell_angle_gamma   70.142
_symmetry_Int_Tables_number   1
_cell_volume   68.958
_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
  Mg  Mg0  1  0.000  0.000  0.000  1.0
  Al  Al1  1  0.500  0.500  0.000  1.0
  Al  Al2  1  0.250  0.750  0.500  1.0
  Al  Al3  1  0.750  0.250  0.500  1.0
[/CIF]
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