data_SrMgAl2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.69
_cell_length_b   5.69
_cell_length_c   3.26
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   109.23
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SrMgAl2
_chemical_formula_sum   'Sr1 Mg1 Al2'
_cell_volume   99.49
_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
  Sr  Sr3  1  0.29  0.0  0.0  1.0
  Mg  Mg2  1  0.0  0.0  0.0  1.0
  Al  Al0  1  0.65  0.68  0.63  1.0
  Al  Al1  1  0.65  0.32  0.63  1.0

data_SrMgAl2
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.26
_cell_length_b   5.69
_cell_length_c   5.69
_cell_angle_alpha   109.23
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SrMgAl2
_chemical_formula_sum   'Sr1 Mg1 Al2'
_cell_volume   99.49
_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
  Sr  Sr0  1  -0.0  0.29  0.0  1.0
  Mg  Mg1  1  0.0  0.0  0.0  1.0
  Al  Al2  1  0.63  0.65  0.32  1.0
  Al  Al3  1  0.63  0.65  0.68  1.0

Sr Mg Al Al
Sr Mg Al Al 0 1 o o o 2 3 o o o 
SrMgAl2 crystallizes in the triclinic P1 space group. Sr(1) is bonded in a 2-coordinate geometry to one Mg(1), two equivalent Al(1), and two equivalent Al(2) atoms. The Sr(1)-Mg(1) bond length is 1.68 Å. There is one shorter (3.35 Å) and one longer (3.73 Å) Sr(1)-Al(1) bond length. There is one shorter (2.53 Å) and one longer (3.02 Å) Sr(1)-Al(2) bond length. Mg(1) is bonded in a 1-coordinate geometry to one Sr(1) and two equivalent Al(1) atoms. There is one shorter (2.53 Å) and one longer (3.02 Å) Mg(1)-Al(1) bond length. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a 5-coordinate geometry to two equivalent Sr(1), two equivalent Mg(1), and one Al(2) atom. The Al(1)-Al(2) bond length is 2.06 Å. In the second Al site, Al(2) is bonded in a 3-coordinate geometry to two equivalent Sr(1) and one Al(1) atom.