data_YMg2Al
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.02
_cell_length_b   5.02
_cell_length_c   5.02
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   YMg2Al
_chemical_formula_sum   'Y1 Mg2 Al1'
_cell_volume   89.45
_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
  Y  Y3  1  0.32  0.32  0.32  1.0
  Mg  Mg1  1  0.77  0.77  0.77  1.0
  Mg  Mg2  1  0.0  0.0  0.0  1.0
  Al  Al0  1  0.55  0.55  0.55  1.0

data_YMg2Al
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.02
_cell_length_b   5.02
_cell_length_c   12.3
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   YMg2Al
_chemical_formula_sum   'Y3 Mg6 Al3'
_cell_volume   268.35
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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
  Y  Y0  3  0.0  0.0  0.68  1.0
  Mg  Mg1  3  0.0  0.0  0.0  1.0
  Mg  Mg2  3  0.0  0.0  0.23  1.0
  Al  Al3  3  0.0  0.0  0.45  1.0

Y Mg Mg Al
Y Mg Mg Al 0 3 o - o 0 3 - o o 0 3 o o - 0 3 o o o 0 2 o o + 0 2 o + o 0 2 + o o 0 1 - o o 0 1 o - o 0 1 o o - 1 2 + o + 1 2 o + + 1 2 + + o 1 2 + + + 1 3 o o o 1 3 o o + 1 3 + o o 1 3 o + o 2 3 - - o 2 3 - o - 2 3 o - - 
Mg2YAl crystallizes in the trigonal R3m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 1-coordinate geometry to four equivalent Mg(2) and four equivalent Al(1) atoms. There is one shorter (2.77 Å) and three longer (3.19 Å) Mg(1)-Mg(2) bond lengths. There is one shorter (2.77 Å) and three longer (3.19 Å) Mg(1)-Al(1) bond lengths. In the second Mg site, Mg(2) is bonded in a 10-coordinate geometry to four equivalent Mg(1), three equivalent Y(1), and three equivalent Al(1) atoms. All Mg(2)-Y(1) bond lengths are 2.90 Å. All Mg(2)-Al(1) bond lengths are 3.24 Å. Y(1) is bonded in a 7-coordinate geometry to three equivalent Mg(2) and four equivalent Al(1) atoms. There is one shorter (2.77 Å) and three longer (3.19 Å) Y(1)-Al(1) bond lengths. Al(1) is bonded in a 11-coordinate geometry to three equivalent Mg(2), four equivalent Mg(1), and four equivalent Y(1) atoms.