The material described by AlMg3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to eight equivalent Mg(2) and four equivalent Al(1) atoms to form MgMg8Al4 cuboctahedra that share corners with four equivalent Mg(1)Mg8Al4 cuboctahedra, corners with eight equivalent Al(1)Mg12 cuboctahedra, edges with eight equivalent Mg(1)Mg8Al4 cuboctahedra, edges with sixteen equivalent Mg(2)Mg8Al4 cuboctahedra, faces with four equivalent Mg(1)Mg8Al4 cuboctahedra, faces with six equivalent Al(1)Mg12 cuboctahedra, and faces with eight equivalent Mg(2)Mg8Al4 cuboctahedra. In the second Mg site, Mg(2) is bonded to four equivalent Mg(1), four equivalent Mg(2), and four equivalent Al(1) atoms to form distorted MgMg8Al4 cuboctahedra that share corners with twelve equivalent Mg(2)Mg8Al4 cuboctahedra, edges with eight equivalent Mg(1)Mg8Al4 cuboctahedra, edges with eight equivalent Mg(2)Mg8Al4 cuboctahedra, edges with eight equivalent Al(1)Mg12 cuboctahedra, faces with four equivalent Mg(1)Mg8Al4 cuboctahedra, faces with four equivalent Al(1)Mg12 cuboctahedra, and faces with ten equivalent Mg(2)Mg8Al4 cuboctahedra. Al(1) is bonded to four equivalent Mg(1) and eight equivalent Mg(2) atoms to form AlMg12 cuboctahedra that share corners with four equivalent Al(1)Mg12 cuboctahedra, corners with eight equivalent Mg(1)Mg8Al4 cuboctahedra, edges with eight equivalent Al(1)Mg12 cuboctahedra, edges with sixteen equivalent Mg(2)Mg8Al4 cuboctahedra, faces with four equivalent Al(1)Mg12 cuboctahedra, faces with six equivalent Mg(1)Mg8Al4 cuboctahedra, and faces with eight equivalent Mg(2)Mg8Al4 cuboctahedra. is represented by the CIF card [CIF]
data_Mg3Al
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.277
_cell_length_b   5.277
_cell_length_c   5.277
_cell_angle_alpha   130.922
_cell_angle_beta   130.922
_cell_angle_gamma   71.937
_symmetry_Int_Tables_number   1
_cell_volume   82.076
_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  0.500  0.500  0.000  1.0
  Mg  Mg1  1  0.250  0.750  0.500  1.0
  Mg  Mg2  1  0.750  0.250  0.500  1.0
  Al  Al3  1  0.000  0.000  0.000  1.0
[/CIF]
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The material described by AlMg3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to eight equivalent Mg(2) and four equivalent Al(1) atoms to form MgMg8Al4 cuboctahedra that share corners with four equivalent Mg(1)Mg8Al4 cuboctahedra, corners with eight equivalent Al(1)Mg12 cuboctahedra, edges with eight equivalent Mg(1)Mg8Al4 cuboctahedra, edges with sixteen equivalent Mg(2)Mg8Al4 cuboctahedra, faces with four equivalent Mg(1)Mg8Al4 cuboctahedra, faces with six equivalent Al(1)Mg12 cuboctahedra, and faces with eight equivalent Mg(2)Mg8Al4 cuboctahedra. In the second Mg site, Mg(2) is bonded to four equivalent Mg(1), four equivalent Mg(2), and four equivalent Al(1) atoms to form distorted MgMg8Al4 cuboctahedra that share corners with twelve equivalent Mg(2)Mg8Al4 cuboctahedra, edges with eight equivalent Mg(1)Mg8Al4 cuboctahedra, edges with eight equivalent Mg(2)Mg8Al4 cuboctahedra, edges with eight equivalent Al(1)Mg12 cuboctahedra, faces with four equivalent Mg(1)Mg8Al4 cuboctahedra, faces with four equivalent Al(1)Mg12 cuboctahedra, and faces with ten equivalent Mg(2)Mg8Al4 cuboctahedra. Al(1) is bonded to four equivalent Mg(1) and eight equivalent Mg(2) atoms to form AlMg12 cuboctahedra that share corners with four equivalent Al(1)Mg12 cuboctahedra, corners with eight equivalent Mg(1)Mg8Al4 cuboctahedra, edges with eight equivalent Al(1)Mg12 cuboctahedra, edges with sixteen equivalent Mg(2)Mg8Al4 cuboctahedra, faces with four equivalent Al(1)Mg12 cuboctahedra, faces with six equivalent Mg(1)Mg8Al4 cuboctahedra, and faces with eight equivalent Mg(2)Mg8Al4 cuboctahedra. is represented by the CIF card [CIF]
data_Mg3Al
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.277
_cell_length_b   5.277
_cell_length_c   5.277
_cell_angle_alpha   130.922
_cell_angle_beta   130.922
_cell_angle_gamma   71.937
_symmetry_Int_Tables_number   1
_cell_volume   82.076
_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  0.500  0.500  0.000  1.0
  Mg  Mg1  1  0.250  0.750  0.500  1.0
  Mg  Mg2  1  0.750  0.250  0.500  1.0
  Al  Al3  1  0.000  0.000  0.000  1.0
[/CIF]
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