data_TaP2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.49
_cell_length_b   4.49
_cell_length_c   4.49
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TaP2Se
_chemical_formula_sum   'Ta1 P2 Se1'
_cell_volume   64.08
_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  Ta3  1  0.18  0.18  0.18  1.0
  P  P0  1  0.76  0.76  0.76  1.0
  P  P1  1  0.59  0.59  0.59  1.0
  Se  Se2  1  0.0  0.0  0.0  1.0

data_TaP2Se
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.49
_cell_length_b   4.49
_cell_length_c   11.0
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   TaP2Se
_chemical_formula_sum   'Ta3 P6 Se3'
_cell_volume   192.23
_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  0.82  1.0
  P  P1  3  0.0  0.0  0.24  1.0
  P  P2  3  0.0  0.0  0.41  1.0
  Se  Se3  3  0.0  0.0  0.0  1.0

Ta P P Se
Ta P P Se 0 3 o o o 1 2 o o o 
TaP2Se crystallizes in the trigonal R3m space group. Ta(1) is bonded in a distorted single-bond geometry to three equivalent P(1), three equivalent P(2), and one Se(1) atom. All Ta(1)-P(1) bond lengths are 2.73 Å. All Ta(1)-P(2) bond lengths are 2.73 Å. The Ta(1)-Se(1) bond length is 1.94 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded in a 8-coordinate geometry to three equivalent Ta(1), one P(2), and four equivalent Se(1) atoms. The P(1)-P(2) bond length is 1.94 Å. There is one shorter (2.59 Å) and three longer (2.81 Å) P(1)-Se(1) bond lengths. In the second P site, P(2) is bonded in a 7-coordinate geometry to three equivalent Ta(1), one P(1), and three equivalent Se(1) atoms. All P(2)-Se(1) bond lengths are 2.73 Å. Se(1) is bonded in a distorted single-bond geometry to one Ta(1), three equivalent P(2), and four equivalent P(1) atoms.