data_MgMnTl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.66
_cell_length_b   4.66
_cell_length_c   4.66
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgMnTl
_chemical_formula_sum   'Mg1 Mn1 Tl1'
_cell_volume   71.36
_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  Mg0  1  0.0  0.0  0.0  1.0
  Mn  Mn1  1  0.29  0.29  0.29  1.0
  Tl  Tl2  1  0.65  0.65  0.65  1.0

data_MgMnTl
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.66
_cell_length_b   4.66
_cell_length_c   11.4
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   MgMnTl
_chemical_formula_sum   'Mg3 Mn3 Tl3'
_cell_volume   214.07
_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
  Mn  Mn1  3  0.0  0.0  0.71  1.0
  Tl  Tl2  3  0.0  0.0  0.35  1.0

Mg Mn Tl
MgMnTl crystallizes in the trigonal R3m space group. Mg(1) is bonded to four equivalent Mn(1) and three equivalent Tl(1) atoms to form MgMn4Tl3 hexagonal pyramids that share corners with three equivalent Mn(1)Mg4Tl3 hexagonal pyramids, corners with six equivalent Mg(1)Mn4Tl3 hexagonal pyramids, edges with three equivalent Mn(1)Mg4Tl3 hexagonal pyramids, and edges with six equivalent Mg(1)Mn4Tl3 hexagonal pyramids. There are three shorter (2.73 Å) and one longer (3.33 Å) Mg(1)-Mn(1) bond length. All Mg(1)-Tl(1) bond lengths are 2.70 Å. Mn(1) is bonded to four equivalent Mg(1) and three equivalent Tl(1) atoms to form MnMg4Tl3 hexagonal pyramids that share corners with three equivalent Mg(1)Mn4Tl3 hexagonal pyramids, corners with six equivalent Mn(1)Mg4Tl3 hexagonal pyramids, edges with three equivalent Mg(1)Mn4Tl3 hexagonal pyramids, and edges with six equivalent Mn(1)Mg4Tl3 hexagonal pyramids. All Mn(1)-Tl(1) bond lengths are 2.70 Å. Tl(1) is bonded in a hexagonal planar geometry to three equivalent Mg(1) and three equivalent Mn(1) atoms.