data_VPSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.51
_cell_length_b   4.51
_cell_length_c   4.51
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   VPSe2
_chemical_formula_sum   'V1 P1 Se2'
_cell_volume   64.93
_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
  V  V3  1  0.6  0.6  0.6  1.0
  P  P0  1  0.0  0.0  0.0  1.0
  Se  Se1  1  0.19  0.19  0.19  1.0
  Se  Se2  1  0.79  0.79  0.79  1.0

data_VPSe2
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.51
_cell_length_b   4.51
_cell_length_c   11.05
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   VPSe2
_chemical_formula_sum   'V3 P3 Se6'
_cell_volume   194.8
_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
  V  V0  3  0.0  0.0  0.4  1.0
  P  P1  3  0.0  0.0  0.0  1.0
  Se  Se2  3  0.0  0.0  0.21  1.0
  Se  Se3  3  0.0  0.0  0.81  1.0

V P Se Se
VPSe2 crystallizes in the trigonal R3m space group. V(1) is bonded in a 1-coordinate geometry to three equivalent P(1), one Se(2), and three equivalent Se(1) atoms. All V(1)-P(1) bond lengths are 2.72 Å. The V(1)-Se(2) bond length is 2.10 Å. All V(1)-Se(1) bond lengths are 2.72 Å. P(1) is bonded in a 5-coordinate geometry to three equivalent V(1), one Se(1), and one Se(2) atom. The P(1)-Se(1) bond length is 2.10 Å. The P(1)-Se(2) bond length is 2.37 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent V(1) and one P(1) atom to form distorted corner-sharing SeV3P tetrahedra. In the second Se site, Se(2) is bonded in a distorted linear geometry to one V(1) and one P(1) atom.