data_Ta2W
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.35
_cell_length_b   5.35
_cell_length_c   5.35
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ta2W
_chemical_formula_sum   'Ta4 W2'
_cell_volume   108.58
_cell_formula_units_Z   2
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
  Ta  Ta0  1  0.73  0.84  0.84  1.0
  Ta  Ta1  1  0.84  0.73  0.84  1.0
  Ta  Ta2  1  0.84  0.84  0.73  1.0
  Ta  Ta3  1  0.73  0.73  0.73  1.0
  W  W4  1  0.89  0.89  0.89  1.0
  W  W5  1  0.0  0.0  0.0  1.0

data_Ta2W
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.35
_cell_length_b   5.35
_cell_length_c   13.12
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Ta2W
_chemical_formula_sum   'Ta12 W6'
_cell_volume   325.73
_cell_formula_units_Z   6
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
  Ta  Ta0  9  0.07  0.04  0.2  1.0
  Ta  Ta1  3  0.0  0.0  0.27  1.0
  W  W2  3  0.0  0.0  0.0  1.0
  W  W3  3  0.0  0.0  0.11  1.0

Ta Ta Ta Ta W W
Ta Ta Ta Ta W W 0 1 o o o 0 2 o o o 0 3 o o o 0 4 o o o 1 2 o o o 1 3 o o o 1 4 o o o 2 3 o o o 2 4 o o o 4 5 + + + 
Ta2W crystallizes in the trigonal R3m space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 5-coordinate geometry to one Ta(2), two equivalent Ta(1), one W(1), and one W(2) atom. The Ta(1)-Ta(2) bond length is 0.99 Å. Both Ta(1)-Ta(1) bond lengths are 0.57 Å. The Ta(1)-W(1) bond length is 1.21 Å. The Ta(1)-W(2) bond length is 3.30 Å. In the second Ta site, Ta(2) is bonded in a 6-coordinate geometry to three equivalent Ta(1) and three equivalent W(2) atoms. All Ta(2)-W(2) bond lengths are 3.21 Å. There are two inequivalent W sites. In the first W site, W(1) is bonded in a distorted rectangular see-saw-like geometry to three equivalent Ta(1) and one W(2) atom. The W(1)-W(2) bond length is 1.40 Å. In the second W site, W(2) is bonded in a 7-coordinate geometry to three equivalent Ta(1), three equivalent Ta(2), and one W(1) atom.