data_Na2TlCr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.18
_cell_length_b   5.18
_cell_length_c   5.18
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na2TlCr
_chemical_formula_sum   'Na2 Tl1 Cr1'
_cell_volume   98.47
_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  Na1  1  0.0  0.0  0.0  1.0
  Na  Na2  1  0.5  0.5  0.5  1.0
  Tl  Tl3  1  0.83  0.83  0.83  1.0
  Cr  Cr0  1  0.67  0.67  0.67  1.0

data_Na2TlCr
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.18
_cell_length_b   5.18
_cell_length_c   12.7
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Na2TlCr
_chemical_formula_sum   'Na6 Tl3 Cr3'
_cell_volume   295.41
_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
  Na  Na1  3  0.0  0.0  0.5  1.0
  Tl  Tl2  3  0.0  0.0  0.17  1.0
  Cr  Cr3  3  0.0  0.0  0.33  1.0

Na Na Tl Cr
Na2CrTl crystallizes in the trigonal R3m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to three equivalent Cr(1) and one Tl(1) atom to form distorted NaTlCr3 trigonal pyramids that share  a cornercorner with one Cr(1)Na4Tl trigonal bipyramid, corners with three equivalent Tl(1)Na4Cr trigonal bipyramids, corners with six equivalent Na(1)TlCr3 trigonal pyramids, and edges with three equivalent Na(2)Tl3Cr trigonal pyramids. All Na(1)-Cr(1) bond lengths are 2.99 Å. The Na(1)-Tl(1) bond length is 2.13 Å. In the second Na site, Na(2) is bonded to one Cr(1) and three equivalent Tl(1) atoms to form distorted NaTl3Cr trigonal pyramids that share  a cornercorner with one Tl(1)Na4Cr trigonal bipyramid, corners with three equivalent Cr(1)Na4Tl trigonal bipyramids, corners with six equivalent Na(2)Tl3Cr trigonal pyramids, and edges with three equivalent Na(1)TlCr3 trigonal pyramids. The Na(2)-Cr(1) bond length is 2.13 Å. All Na(2)-Tl(1) bond lengths are 2.99 Å. Cr(1) is bonded to one Na(2), three equivalent Na(1), and one Tl(1) atom to form distorted CrNa4Tl trigonal bipyramids that share corners with six equivalent Cr(1)Na4Tl trigonal bipyramids,  a cornercorner with one Na(1)TlCr3 trigonal pyramid, corners with three equivalent Na(2)Tl3Cr trigonal pyramids, and edges with three equivalent Tl(1)Na4Cr trigonal bipyramids. The Cr(1)-Tl(1) bond length is 2.13 Å. Tl(1) is bonded to one Na(1), three equivalent Na(2), and one Cr(1) atom to form distorted TlNa4Cr trigonal bipyramids that share corners with six equivalent Tl(1)Na4Cr trigonal bipyramids,  a cornercorner with one Na(2)Tl3Cr trigonal pyramid, corners with three equivalent Na(1)TlCr3 trigonal pyramids, and edges with three equivalent Cr(1)Na4Tl trigonal bipyramids.