data_Ta2PSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.53
_cell_length_b   8.53
_cell_length_c   8.53
_cell_angle_alpha   22.37
_cell_angle_beta   22.37
_cell_angle_gamma   22.37
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ta2PSe
_chemical_formula_sum   'Ta2 P1 Se1'
_cell_volume   78.75
_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  Ta2  1  0.0  0.0  0.02  1.0
  Ta  Ta3  1  0.0  0.0  0.12  1.0
  P  P0  1  0.0  0.0  0.86  1.0
  Se  Se1  1  0.0  0.0  0.39  1.0

data_Ta2PSe
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.73
_cell_length_b   3.31
_cell_length_c   8.53
_cell_angle_alpha   90.0
_cell_angle_beta   102.94
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Ta2PSe
_chemical_formula_sum   'Ta4 P2 Se2'
_cell_volume   157.49
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  2  0.0  0.0  0.88  1.0
  Ta  Ta1  2  0.0  0.0  0.98  1.0
  P  P2  2  0.0  0.0  0.14  1.0
  Se  Se3  2  0.0  0.0  0.61  1.0

Ta Ta P Se
Ta2PSe is Cyanogen Chloride-like structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two Ta2PSe clusters. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a distorted linear geometry to one Ta(2) and one P(1) atom. The Ta(1)-Ta(2) bond length is 0.92 Å. The Ta(1)-P(1) bond length is 1.33 Å. In the second Ta site, Ta(2) is bonded in a linear geometry to one Ta(1) and one Se(1) atom. The Ta(2)-Se(1) bond length is 2.28 Å. P(1) is bonded in a single-bond geometry to one Ta(1) atom. Se(1) is bonded in a single-bond geometry to one Ta(2) atom.