data_PO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.49
_cell_length_b   4.49
_cell_length_c   2.84
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   PO2
_chemical_formula_sum   'P2 O4'
_cell_volume   57.19
_cell_formula_units_Z   2
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
  P  P4  1  0.0  0.0  0.0  1.0
  P  P5  1  0.24  0.24  0.42  1.0
  O  O0  1  0.37  0.37  0.0  1.0
  O  O1  1  0.12  0.12  0.0  1.0
  O  O2  1  0.61  0.87  0.42  1.0
  O  O3  1  0.87  0.61  0.42  1.0

data_PO2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.35
_cell_length_b   6.35
_cell_length_c   2.84
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   PO2
_chemical_formula_sum   'P4 O8'
_cell_volume   114.38
_cell_formula_units_Z   4
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
  P  P0  2  0.0  0.0  0.0  1.0
  P  P1  2  0.24  0.0  0.42  1.0
  O  O2  4  0.24  0.37  0.42  1.0
  O  O3  2  0.12  0.0  0.0  1.0
  O  O4  2  0.37  0.0  0.0  1.0

P P O O O O
P P O O O O 0 3 o o o 1 3 o o o 1 2 o o o 2 3 o o o 4 5 o o o 
PO2 crystallizes in the monoclinic Cm space group. There are two inequivalent P sites. In the first P site, P(1) is bonded in a single-bond geometry to one O(2) and four equivalent O(3) atoms. The P(1)-O(2) bond length is 0.76 Å. There are two shorter (2.17 Å) and two longer (2.46 Å) P(1)-O(3) bond lengths. In the second P site, P(2) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. There is one shorter (1.43 Å) and one longer (1.83 Å) P(2)-O(1) bond length. There is one shorter (1.43 Å) and one longer (1.83 Å) P(2)-O(2) bond length. Both P(2)-O(3) bond lengths are 2.35 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to two equivalent P(2) atoms. In the second O site, O(2) is bonded in a 1-coordinate geometry to one P(1) and two equivalent P(2) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to one P(2), two equivalent P(1), and one O(3) atom. The O(3)-O(3) bond length is 1.65 Å.