data_Ta4Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.95
_cell_length_b   7.95
_cell_length_c   7.95
_cell_angle_alpha   109.47
_cell_angle_beta   109.47
_cell_angle_gamma   109.47
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ta4Si
_chemical_formula_sum   'Ta16 Si4'
_cell_volume   386.78
_cell_formula_units_Z   4
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  Ta4  1  0.87  0.87  0.87  1.0
  Ta  Ta5  1  0.28  0.72  0.72  1.0
  Ta  Ta6  1  0.72  0.28  0.72  1.0
  Ta  Ta7  1  0.72  0.72  0.28  1.0
  Ta  Ta8  1  0.0  0.0  0.08  1.0
  Ta  Ta9  1  0.0  0.0  0.1  1.0
  Ta  Ta10  1  0.0  0.08  0.0  1.0
  Ta  Ta11  1  0.0  0.1  0.0  1.0
  Ta  Ta12  1  0.08  0.0  0.0  1.0
  Ta  Ta13  1  0.1  0.0  0.0  1.0
  Ta  Ta14  1  0.59  0.0  0.29  1.0
  Ta  Ta15  1  0.0  0.59  0.29  1.0
  Ta  Ta16  1  0.0  0.29  0.59  1.0
  Ta  Ta17  1  0.59  0.29  0.0  1.0
  Ta  Ta18  1  0.29  0.59  0.0  1.0
  Ta  Ta19  1  0.29  0.0  0.59  1.0
  Si  Si0  1  0.1  0.1  0.1  1.0
  Si  Si1  1  0.51  0.49  0.49  1.0
  Si  Si2  1  0.49  0.51  0.49  1.0
  Si  Si3  1  0.49  0.49  0.51  1.0

data_Ta4Si
_symmetry_space_group_name_H-M   R3m
_cell_length_a   12.98
_cell_length_b   12.98
_cell_length_c   7.95
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Ta4Si
_chemical_formula_sum   'Ta48 Si12'
_cell_volume   1160.35
_cell_formula_units_Z   12
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+2/3, y+1/3, z+1/3'
  8  '-y+2/3, x-y+1/3, z+1/3'
  9  '-x+y+2/3, -x+1/3, z+1/3'
  10  '-y+2/3, -x+1/3, z+1/3'
  11  '-x+y+2/3, y+1/3, z+1/3'
  12  'x+2/3, x-y+1/3, z+1/3'
  13  'x+1/3, y+2/3, z+2/3'
  14  '-y+1/3, x-y+2/3, z+2/3'
  15  '-x+y+1/3, -x+2/3, z+2/3'
  16  '-y+1/3, -x+2/3, z+2/3'
  17  '-x+y+1/3, y+2/3, z+2/3'
  18  'x+1/3, x-y+2/3, z+2/3'
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  18  0.0  0.29  0.29  1.0
  Ta  Ta1  9  0.04  0.52  0.24  1.0
  Ta  Ta2  9  0.06  0.03  0.03  1.0
  Ta  Ta3  9  0.06  0.03  0.03  1.0
  Ta  Ta4  3  0.0  0.0  0.87  1.0
  Si  Si5  9  0.02  0.01  0.5  1.0
  Si  Si6  3  0.0  0.0  0.1  1.0

Ta Ta Ta Ta Ta Ta Ta Ta Ta Ta Ta Ta Ta Ta Ta Ta Si Si Si Si
Ta7Si(Ta3Si)3 crystallizes in the trigonal R3m space group. The structure consists of three Ta7Si clusters inside a Ta3Si framework. In each Ta7Si cluster, there are three inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 3-coordinate geometry to three equivalent Ta(3) atoms. All Ta(1)-Ta(3) bond lengths are 1.40 Å. In the second Ta site, Ta(3) is bonded in a bent 120 degrees geometry to one Ta(1), one Ta(4), and one Si(1) atom. The Ta(3)-Ta(4) bond length is 0.12 Å. The Ta(3)-Si(1) bond length is 0.86 Å. In the third Ta site, Ta(4) is bonded in a single-bond geometry to one Ta(3) atom. Si(1) is bonded in a 3-coordinate geometry to three equivalent Ta(3) atoms. In the Ta3Si framework, there are two inequivalent Ta sites. In the first Ta site, Ta(2) is bonded in a 6-coordinate geometry to four equivalent Ta(5) and two equivalent Si(2) atoms. There are two shorter (2.73 Å) and two longer (2.93 Å) Ta(2)-Ta(5) bond lengths. Both Ta(2)-Si(2) bond lengths are 3.27 Å. In the second Ta site, Ta(5) is bonded in a 4-coordinate geometry to two equivalent Ta(2) and two equivalent Ta(5) atoms. Both Ta(5)-Ta(5) bond lengths are 2.79 Å. Si(2) is bonded in a 2-coordinate geometry to two equivalent Ta(2) and two equivalent Si(2) atoms. Both Si(2)-Si(2) bond lengths are 0.34 Å.