data_SrMgTl2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.83
_cell_length_b   3.83
_cell_length_c   7.87
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SrMgTl2
_chemical_formula_sum   'Sr1 Mg1 Tl2'
_cell_volume   115.2
_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  0.0  0.0  0.94  1.0
  Mg  Mg0  1  0.0  0.0  0.0  1.0
  Tl  Tl2  1  0.91  0.91  0.19  1.0
  Tl  Tl3  1  0.91  0.91  0.68  1.0

data_SrMgTl2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.41
_cell_length_b   5.41
_cell_length_c   7.87
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   SrMgTl2
_chemical_formula_sum   'Sr2 Mg2 Tl4'
_cell_volume   230.41
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  2  0.0  0.0  0.94  1.0
  Mg  Mg1  2  0.0  0.0  0.0  1.0
  Tl  Tl2  2  0.41  0.5  0.19  1.0
  Tl  Tl3  2  0.41  0.5  0.68  1.0

Sr Mg Tl Tl
Sr Mg Tl Tl 0 1 o o + 0 3 - - o 1 2 - - o 
SrMgTl2 crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two SrMgTl2 clusters. Sr(1) is bonded in a distorted linear geometry to one Mg(1) and one Tl(2) atom. The Sr(1)-Mg(1) bond length is 0.50 Å. The Sr(1)-Tl(2) bond length is 2.04 Å. Mg(1) is bonded in a distorted linear geometry to one Sr(1) and one Tl(1) atom. The Mg(1)-Tl(1) bond length is 1.56 Å. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a single-bond geometry to one Mg(1) atom. In the second Tl site, Tl(2) is bonded in a single-bond geometry to one Sr(1) atom.