data_MgTl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.75
_cell_length_b   3.75
_cell_length_c   7.37
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgTl
_chemical_formula_sum   'Mg2 Tl2'
_cell_volume   103.79
_cell_formula_units_Z   2
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  Mg0  1  0.88  0.0  0.47  1.0
  Mg  Mg1  1  0.0  0.88  0.89  1.0
  Tl  Tl2  1  0.88  0.0  0.62  1.0
  Tl  Tl3  1  0.0  0.88  0.74  1.0

data_MgTl
_symmetry_space_group_name_H-M   C2/m
_cell_length_a   5.31
_cell_length_b   5.31
_cell_length_c   7.37
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   12
_chemical_formula_structural   MgTl
_chemical_formula_sum   'Mg4 Tl4'
_cell_volume   207.58
_cell_formula_units_Z   4
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-x, -y, -z'
  3  '-x, y, -z'
  4  'x, -y, z'
  5  'x+1/2, y+1/2, z'
  6  '-x+1/2, -y+1/2, -z'
  7  '-x+1/2, y+1/2, -z'
  8  '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
  Mg  Mg0  4  0.06  0.0  0.71  1.0
  Tl  Tl1  4  0.06  0.0  0.56  1.0

Mg Mg Tl Tl
Mg Mg Tl Tl 0 2 o o o 1 3 o o o 2 3 + - o 