The material described by La(Mg2Al)4 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 12-coordinate geometry to two equivalent Mg(1), four equivalent Mg(2), two equivalent La(1), and four equivalent Al(1) atoms. In the second Mg site, Mg(2) is bonded in a 10-coordinate geometry to one Mg(2), four equivalent Mg(1), one La(1), and four equivalent Al(1) atoms. La(1) is bonded in a 20-coordinate geometry to four equivalent Mg(2), eight equivalent Mg(1), and eight equivalent Al(1) atoms. Al(1) is bonded in a 12-coordinate geometry to four equivalent Mg(1), four equivalent Mg(2), two equivalent La(1), and two equivalent Al(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_La(Mg2Al)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.555
_cell_length_b   7.555
_cell_length_c   7.555
_cell_angle_alpha   98.570
_cell_angle_beta   98.570
_cell_angle_gamma   134.584
_symmetry_Int_Tables_number   1
_cell_volume   283.341
_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
  La  La0  1  0.000  0.000  0.000  1.0
  Mg  Mg1  1  0.284  0.500  0.784  1.0
  Mg  Mg2  1  0.716  0.500  0.216  1.0
  Mg  Mg3  1  0.500  0.284  0.784  1.0
  Mg  Mg4  1  0.500  0.716  0.216  1.0
  Mg  Mg5  1  0.348  0.000  0.348  1.0
  Mg  Mg6  1  0.652  0.000  0.652  1.0
  Mg  Mg7  1  0.000  0.348  0.348  1.0
  Mg  Mg8  1  0.000  0.652  0.652  1.0
  Al  Al9  1  0.500  0.500  0.500  1.0
  Al  Al10  1  0.000  0.000  0.500  1.0
  Al  Al11  1  0.000  0.500  0.000  1.0
  Al  Al12  1  0.500  0.000  0.000  1.0
[/CIF]
.
The material described by La(Mg2Al)4 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 12-coordinate geometry to two equivalent Mg(1), four equivalent Mg(2), two equivalent La(1), and four equivalent Al(1) atoms. In the second Mg site, Mg(2) is bonded in a 10-coordinate geometry to one Mg(2), four equivalent Mg(1), one La(1), and four equivalent Al(1) atoms. La(1) is bonded in a 20-coordinate geometry to four equivalent Mg(2), eight equivalent Mg(1), and eight equivalent Al(1) atoms. Al(1) is bonded in a 12-coordinate geometry to four equivalent Mg(1), four equivalent Mg(2), two equivalent La(1), and two equivalent Al(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_La(Mg2Al)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.555
_cell_length_b   7.555
_cell_length_c   7.555
_cell_angle_alpha   98.570
_cell_angle_beta   98.570
_cell_angle_gamma   134.584
_symmetry_Int_Tables_number   1
_cell_volume   283.341
_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
  La  La0  1  0.000  0.000  0.000  1.0
  Mg  Mg1  1  0.284  0.500  0.784  1.0
  Mg  Mg2  1  0.716  0.500  0.216  1.0
  Mg  Mg3  1  0.500  0.284  0.784  1.0
  Mg  Mg4  1  0.500  0.716  0.216  1.0
  Mg  Mg5  1  0.348  0.000  0.348  1.0
  Mg  Mg6  1  0.652  0.000  0.652  1.0
  Mg  Mg7  1  0.000  0.348  0.348  1.0
  Mg  Mg8  1  0.000  0.652  0.652  1.0
  Al  Al9  1  0.500  0.500  0.500  1.0
  Al  Al10  1  0.000  0.000  0.500  1.0
  Al  Al11  1  0.000  0.500  0.000  1.0
  Al  Al12  1  0.500  0.000  0.000  1.0
[/CIF]
.