data_Ba2PSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.74
_cell_length_b   5.74
_cell_length_c   3.81
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ba2PSe
_chemical_formula_sum   'Ba2 P1 Se1'
_cell_volume   125.76
_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
  Ba  Ba0  1  0.87  0.0  0.91  1.0
  Ba  Ba1  1  0.0  0.87  0.91  1.0
  P  P2  1  0.0  0.0  0.0  1.0
  Se  Se3  1  0.87  0.87  0.0  1.0

data_Ba2PSe
_symmetry_space_group_name_H-M   Cm
_cell_length_a   8.12
_cell_length_b   8.12
_cell_length_c   3.81
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Ba2PSe
_chemical_formula_sum   'Ba4 P2 Se2'
_cell_volume   251.52
_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
  Ba  Ba0  4  0.44  0.44  0.91  1.0
  P  P1  2  0.0  0.0  0.0  1.0
  Se  Se2  2  0.37  0.5  0.0  1.0

Ba Ba P Se
Ba2PSe crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two Ba2PSe clusters. Ba(1) is bonded in a distorted L-shaped geometry to one P(1) and one Se(1) atom. The Ba(1)-P(1) bond length is 0.82 Å. The Ba(1)-Se(1) bond length is 0.82 Å. P(1) is bonded in a 2-coordinate geometry to two equivalent Ba(1) atoms. Se(1) is bonded in a 2-coordinate geometry to two equivalent Ba(1) atoms.