data_CrP2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.55
_cell_length_b   3.55
_cell_length_c   5.22
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CrP2Se
_chemical_formula_sum   'Cr1 P2 Se1'
_cell_volume   65.7
_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
  Cr  Cr0  1  0.0  0.0  0.0  1.0
  P  P1  1  0.0  0.77  0.61  1.0
  P  P2  1  0.77  0.0  0.61  1.0
  Se  Se3  1  0.77  0.77  0.0  1.0

data_CrP2Se
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.02
_cell_length_b   5.02
_cell_length_c   5.22
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   CrP2Se
_chemical_formula_sum   'Cr2 P4 Se2'
_cell_volume   131.4
_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
  Cr  Cr0  2  0.0  0.0  0.0  1.0
  P  P1  4  0.39  0.39  0.61  1.0
  Se  Se2  2  0.27  0.5  0.0  1.0

Cr P P Se
Cr P P Se 0 3 - - o 1 2 - + o 
CrP2Se crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two CrP2Se clusters. Cr(1) is bonded in a single-bond geometry to two equivalent P(1) and one Se(1) atom. Both Cr(1)-P(1) bond lengths are 2.20 Å. The Cr(1)-Se(1) bond length is 1.13 Å. P(1) is bonded in a 3-coordinate geometry to one Cr(1), one P(1), and one Se(1) atom. The P(1)-P(1) bond length is 1.13 Å. The P(1)-Se(1) bond length is 2.20 Å. Se(1) is bonded in a single-bond geometry to one Cr(1) and two equivalent P(1) atoms.