data_TaCuSn3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.96
_cell_length_b   4.96
_cell_length_c   4.96
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TaCuSn3
_chemical_formula_sum   'Ta1 Cu1 Sn3'
_cell_volume   121.88
_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
  Ta  Ta4  1  0.48  0.48  0.48  1.0
  Cu  Cu3  1  0.0  0.0  0.0  1.0
  Sn  Sn0  1  0.0  0.48  0.0  1.0
  Sn  Sn1  1  0.0  0.0  0.48  1.0
  Sn  Sn2  1  0.48  0.0  0.0  1.0

data_TaCuSn3
_symmetry_space_group_name_H-M   R3m
_cell_length_a   7.01
_cell_length_b   7.01
_cell_length_c   8.59
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   TaCuSn3
_chemical_formula_sum   'Ta3 Cu3 Sn9'
_cell_volume   365.63
_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
  Ta  Ta0  3  0.0  0.0  0.48  1.0
  Cu  Cu1  3  0.0  0.0  0.0  1.0
  Sn  Sn2  9  0.17  0.35  0.83  1.0

Ta Cu Sn Sn Sn
TaCuSn3 is (Cubic) Perovskite structured and crystallizes in the trigonal R3m space group. Ta(1) is bonded to twelve equivalent Sn(1) atoms to form TaSn12 cuboctahedra that share corners with twelve equivalent Ta(1)Sn12 cuboctahedra, faces with six equivalent Ta(1)Sn12 cuboctahedra, and faces with eight equivalent Cu(1)Sn6 octahedra. There are a spread of Ta(1)-Sn(1) bond distances ranging from 3.36-3.65 Å. Cu(1) is bonded to six equivalent Sn(1) atoms to form CuSn6 octahedra that share corners with six equivalent Cu(1)Sn6 octahedra and faces with eight equivalent Ta(1)Sn12 cuboctahedra. The corner-sharing octahedra are not tilted. There are three shorter (2.37 Å) and three longer (2.58 Å) Cu(1)-Sn(1) bond lengths. Sn(1) is bonded in a 6-coordinate geometry to four equivalent Ta(1) and two equivalent Cu(1) atoms.