data_MgZrTl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.79
_cell_length_b   4.79
_cell_length_c   4.79
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgZrTl
_chemical_formula_sum   'Mg1 Zr1 Tl1'
_cell_volume   77.65
_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
  Zr  Zr2  1  0.39  0.39  0.39  1.0
  Tl  Tl1  1  0.69  0.69  0.69  1.0

data_MgZrTl
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.79
_cell_length_b   4.79
_cell_length_c   11.73
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   MgZrTl
_chemical_formula_sum   'Mg3 Zr3 Tl3'
_cell_volume   232.95
_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
  Zr  Zr1  3  0.0  0.0  0.61  1.0
  Tl  Tl2  3  0.0  0.0  0.31  1.0

Mg Zr Tl
Mg Zr Tl 0 2 - - o 0 2 - o - 0 2 o - - 0 1 - o o 0 1 o - o 0 1 o o - 1 2 - o o 1 2 o - o 1 2 o o - 
MgZrTl is half-Heusler structured and crystallizes in the trigonal R3m space group. Mg(1) is bonded in a 7-coordinate geometry to three equivalent Zr(1) and four equivalent Tl(1) atoms. All Mg(1)-Zr(1) bond lengths are 2.83 Å. There are three shorter (2.78 Å) and one longer (3.60 Å) Mg(1)-Tl(1) bond length. Zr(1) is bonded to three equivalent Mg(1) and four equivalent Tl(1) atoms to form a mixture of distorted edge and corner-sharing ZrMg3Tl4 hexagonal pyramids. There are three shorter (2.78 Å) and one longer (3.60 Å) Zr(1)-Tl(1) bond length. Tl(1) is bonded in a 8-coordinate geometry to four equivalent Mg(1) and four equivalent Zr(1) atoms.