data_NaMg2Tl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.22
_cell_length_b   5.22
_cell_length_c   5.22
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaMg2Tl
_chemical_formula_sum   'Na1 Mg2 Tl1'
_cell_volume   100.39
_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
  Na  Na2  1  0.0  0.0  0.0  1.0
  Mg  Mg0  1  0.69  0.69  0.69  1.0
  Mg  Mg1  1  0.84  0.84  0.84  1.0
  Tl  Tl3  1  0.53  0.53  0.53  1.0

data_NaMg2Tl
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.22
_cell_length_b   5.22
_cell_length_c   12.78
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   NaMg2Tl
_chemical_formula_sum   'Na3 Mg6 Tl3'
_cell_volume   301.17
_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
  Na  Na0  3  0.0  0.0  0.0  1.0
  Mg  Mg1  3  0.0  0.0  0.16  1.0
  Mg  Mg2  3  0.0  0.0  0.31  1.0
  Tl  Tl3  3  0.0  0.0  0.47  1.0

Na Mg Mg Tl
NaMg2Tl crystallizes in the trigonal R3m space group. Na(1) is bonded in a distorted single-bond geometry to one Mg(2) and three equivalent Mg(1) atoms. The Na(1)-Mg(2) bond length is 1.99 Å. All Na(1)-Mg(1) bond lengths are 3.03 Å. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to three equivalent Na(1), one Mg(2), and one Tl(1) atom to form distorted corner-sharing MgNa3MgTl trigonal bipyramids. The Mg(1)-Mg(2) bond length is 1.99 Å. The Mg(1)-Tl(1) bond length is 1.99 Å. In the second Mg site, Mg(2) is bonded in a 5-coordinate geometry to one Na(1), one Mg(1), and three equivalent Tl(1) atoms. All Mg(2)-Tl(1) bond lengths are 3.03 Å. Tl(1) is bonded in a distorted single-bond geometry to one Mg(1) and three equivalent Mg(2) atoms.