data_NaTa2Cr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.53
_cell_length_b   4.53
_cell_length_c   4.53
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaTa2Cr
_chemical_formula_sum   'Na1 Ta2 Cr1'
_cell_volume   65.68
_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
  Ta  Ta2  1  0.6  0.6  0.6  1.0
  Ta  Ta3  1  0.8  0.8  0.8  1.0
  Cr  Cr0  1  0.2  0.2  0.2  1.0

data_NaTa2Cr
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.53
_cell_length_b   4.53
_cell_length_c   11.09
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   NaTa2Cr
_chemical_formula_sum   'Na3 Ta6 Cr3'
_cell_volume   197.04
_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
  Ta  Ta1  3  0.0  0.0  0.2  1.0
  Ta  Ta2  3  0.0  0.0  0.4  1.0
  Cr  Cr3  3  0.0  0.0  0.8  1.0

Na Ta Ta Cr
NaTa2Cr crystallizes in the trigonal R3m space group. Na(1) is bonded in a distorted linear geometry to one Ta(2), three equivalent Ta(1), and one Cr(1) atom. The Na(1)-Ta(2) bond length is 2.18 Å. All Na(1)-Ta(1) bond lengths are 2.71 Å. The Na(1)-Cr(1) bond length is 2.24 Å. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 7-coordinate geometry to three equivalent Na(1), one Ta(2), and three equivalent Cr(1) atoms. The Ta(1)-Ta(2) bond length is 2.24 Å. All Ta(1)-Cr(1) bond lengths are 2.71 Å. In the second Ta site, Ta(2) is bonded in a distorted single-bond geometry to one Na(1) and one Ta(1) atom. Cr(1) is bonded in a distorted single-bond geometry to one Na(1) and three equivalent Ta(1) atoms.