S2O22- ion

 O3 \ S1 - S2 - O4
The ion charge is -2.

Atomic Charges and Dipole Moment

S1 charge=-0.333
S2 charge=-0.334
O3 charge=-0.667
O4 charge=-0.665
with a dipole moment of 2.94063 Debye

Bond Lengths:

between S1 and S2: distance=2.232 ang___ between S1 and O3: distance=1.649 ang___
between S2 and O4: distance=1.646 ang___

Bond Angles:

for O3-S1-S2: angle=120.4 deg___ for O4-S2-S1: angle=120.3 deg___

Bond Orders (Mulliken):

between S1 and S2: order=0.714___ between S1 and O3: order=0.759___
between S2 and O4: order=0.759___

Best Lewis Structure

The Lewis structure that is closest to your structure is determined. The hybridization of the atoms in this idealized Lewis structure is given in the table below. Please note that your structure can't be well described by a single Lewis structure, because of extensive delocalization.

Hybridization in the Best Lewis Structure

1. A bonding orbital for S1-S2 with 1.9785 electrons
__has 50.04% S 1 character in a s0.30 p3 hybrid
__has 49.96% S 2 character in a s0.30 p3 hybrid

2. A bonding orbital for S1-O3 with 1.9942 electrons
__has 37.98% S 1 character in a s0.62 p3 d0.05 hybrid
__has 62.02% O 3 character in a s0.61 p3 hybrid

3. A bonding orbital for S2-O4 with 1.9942 electrons
__has 37.88% S 2 character in a s0.62 p3 d0.05 hybrid
__has 62.12% O 4 character in a s0.62 p3 hybrid

16. A lone pair orbital for S1 with 1.9955 electrons

17. A lone pair orbital for S1 with 1.9447 electrons
__made from a s0.10 p3 hybrid

18. A lone pair orbital for S2 with 1.9955 electrons

19. A lone pair orbital for S2 with 1.9445 electrons
__made from a s0.10 p3 hybrid

20. A lone pair orbital for O3 with 1.9966 electrons

21. A lone pair orbital for O3 with 1.9830 electrons

22. A lone pair orbital for O3 with 1.8946 electrons
__made from a s0.11 p3 hybrid

23. A lone pair orbital for O4 with 1.9966 electrons

24. A lone pair orbital for O4 with 1.9828 electrons

25. A lone pair orbital for O4 with 1.8935 electrons
__made from a s0.11 p3 hybrid

108. A antibonding orbital for S1-S2 with 0.1712 electrons
__has 49.96% S 1 character in a s0.30 p3 hybrid
__has 50.04% S 2 character in a s0.30 p3 hybrid

-With core pairs on: S 1 S 1 S 1 S 1 S 1 S 2 S 2 S 2 S 2 S 2 O 3 O 4 -

Donor Acceptor Interactions in the Best Lewis Structure

The localized orbitals in your best Lewis structure can interact strongly. A filled bonding or lone pair orbital can act as a donor and an empty or filled bonding, antibonding, or lone pair orbital can act as an acceptor. These interactions can strengthen and weaken bonds. For example, a lone pair donor->antibonding acceptor orbital interaction will weaken the bond associated with the antibonding orbital. Conversly, an interaction with a bonding pair as the acceptor will strengthen the bond. Strong electron delocalization in your best Lewis structure will also show up as donor-acceptor interactions.
Interactions greater than 20 kJ/mol for bonding and lone pair orbitals are listed below.

The interaction of the second lone pair donor orbital, 17, for S1 with the antibonding acceptor orbital, 110, for S2-O4 is 40.4 kJ/mol.

The interaction of the second lone pair donor orbital, 19, for S2 with the antibonding acceptor orbital, 109, for S1-O3 is 40.5 kJ/mol.

The interaction of the third lone pair donor orbital, 22, for O3 with the antibonding acceptor orbital, 108, for S1-S2 is 117. kJ/mol.

The interaction of the third lone pair donor orbital, 25, for O4 with the antibonding acceptor orbital, 108, for S1-S2 is 118. kJ/mol.

Molecular Orbital Energies

The orbital energies are given in eV, where 1 eV=96.49 kJ/mol. Orbitals with very low energy are core 1s orbitals. More antibonding orbitals than you might expect are sometimes listed, because d orbitals are always included for heavy atoms and p orbitals are included for H atoms. Up spins are shown with a ^ and down spins are shown as v.

29 ----- 14.92

28 ----- 10.18
27 ----- 9.935

26 ----- 8.244

25 -^-v- 6.127 24 -^-v- 6.106

23 -^-v- 5.296

22 -^-v- 3.504

21 -^-v- 2.697
20 -^-v- 2.588

19 -^-v- 1.554
18 -^-v- 1.471

17 -^-v- 0.453

16 -^-v- -3.646

15 -^-v- -6.557

14 -^-v- -12.36

13 -^-v- -12.59

12 -^-v- -144.8 11 -^-v- -144.9

10 -^-v- -145.1 9 -^-v- -145.1
8 -^-v- -145.2
7 -^-v- -145.2

6 -^-v- -197.9 5 -^-v- -197.9

4 -^-v- -494.6 3 -^-v- -494.6

2 -^-v- -2377. 1 -^-v- -2377.

Total Electronic Energy

The total electronic energy is a very large number, so by convention the units are given in atomic units, that is Hartrees (H). One Hartree is 2625.5 kJ/mol. The energy reference is for totally dissociated atoms. In other words, the reference state is a gas consisting of nuclei and electrons all at infinite distance from each other. The electronic energy includes all electric interactions and the kinetic energy of the electrons. This energy does not include translation, rotation, or vibration of the the molecule.

Total electronic energy = -946.8574215600 Hartrees