data_SrMgTl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.33
_cell_length_b   5.33
_cell_length_c   5.33
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SrMgTl
_chemical_formula_sum   'Sr1 Mg1 Tl1'
_cell_volume   107.08
_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  Sr1  1  0.77  0.77  0.77  1.0
  Mg  Mg0  1  0.0  0.0  0.0  1.0
  Tl  Tl2  1  0.65  0.65  0.65  1.0

data_SrMgTl
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.33
_cell_length_b   5.33
_cell_length_c   13.06
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   SrMgTl
_chemical_formula_sum   'Sr3 Mg3 Tl3'
_cell_volume   321.24
_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
  Sr  Sr0  3  0.0  0.0  0.23  1.0
  Mg  Mg1  3  0.0  0.0  0.0  1.0
  Tl  Tl2  3  0.0  0.0  0.35  1.0

Sr Mg Tl
Sr Mg Tl 0 2 o o o 0 1 + + + 0 1 + + o 0 1 o + + 0 1 + o + 1 2 - - o 1 2 - o - 1 2 o - - 
SrMgTl crystallizes in the trigonal R3m space group. Sr(1) is bonded in a single-bond geometry to four equivalent Mg(1) and one Tl(1) atom. There is one shorter (3.02 Å) and three longer (3.35 Å) Sr(1)-Mg(1) bond lengths. The Sr(1)-Tl(1) bond length is 1.51 Å. Mg(1) is bonded in a 7-coordinate geometry to four equivalent Sr(1) and three equivalent Tl(1) atoms. All Mg(1)-Tl(1) bond lengths are 3.08 Å. Tl(1) is bonded in a single-bond geometry to one Sr(1) and three equivalent Mg(1) atoms.