data_Mg2TlCl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.38
_cell_length_b   5.38
_cell_length_c   5.38
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2TlCl
_chemical_formula_sum   'Mg2 Tl1 Cl1'
_cell_volume   110.31
_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
  Mg  Mg1  1  0.0  0.0  0.0  1.0
  Mg  Mg2  1  0.9  0.9  0.9  1.0
  Tl  Tl3  1  0.71  0.71  0.71  1.0
  Cl  Cl0  1  0.81  0.81  0.81  1.0

data_Mg2TlCl
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.38
_cell_length_b   5.38
_cell_length_c   13.19
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Mg2TlCl
_chemical_formula_sum   'Mg6 Tl3 Cl3'
_cell_volume   330.93
_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
  Mg  Mg0  3  0.0  0.0  -0.0  1.0
  Mg  Mg1  3  0.0  0.0  0.1  1.0
  Tl  Tl2  3  0.0  0.0  0.29  1.0
  Cl  Cl3  3  0.0  0.0  0.19  1.0

Mg Mg Tl Cl
Mg Mg Tl Cl 0 1 - - - 1 3 o o o 2 3 o o o 
Mg2TlCl crystallizes in the trigonal R3m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one Mg(2) and three equivalent Tl(1) atoms to form distorted corner-sharing MgMgTl3 trigonal pyramids. The Mg(1)-Mg(2) bond length is 1.28 Å. All Mg(1)-Tl(1) bond lengths are 3.16 Å. In the second Mg site, Mg(2) is bonded in a distorted single-bond geometry to one Mg(1) and one Cl(1) atom. The Mg(2)-Cl(1) bond length is 1.28 Å. Tl(1) is bonded in a single-bond geometry to three equivalent Mg(1) and one Cl(1) atom. The Tl(1)-Cl(1) bond length is 1.28 Å. Cl(1) is bonded in a linear geometry to one Mg(2) and one Tl(1) atom.