## O2COO2-, Peroxocarbonate ion

 O3 \ C1 - O2 / \ O4 O5
The ion charge is -2.

## Atomic Charges and Dipole Moment

C1 charge= 1.090
O2 charge=-0.449
O3 charge=-0.977
O4 charge=-0.886
O5 charge=-0.777
with a dipole moment of 1.83667 Debye

## Bond Lengths:

between C1 and O2: distance=1.402 ang___ between C1 and O3: distance=1.299 ang___
between C1 and O4: distance=1.272 ang___ between C1 and O5: distance=2.526 ang___
between O2 and O3: distance=2.222 ang___ between O2 and O4: distance=2.347 ang___
between O2 and O5: distance=1.524 ang___ between O3 and O4: distance=2.298 ang___
between O4 and O5: distance=2.847 ang___

## Bond Angles:

for O3-C1-O2: angle=110.6 deg___ for O4-C1-O2: angle=122.6 deg___
for O5-O2-C1: angle=119.3 deg___

## Bond Orders (Mulliken):

between C1 and O2: order=1.055___ between C1 and O3: order=1.482___
between C1 and O4: order=1.646___ between C1 and O5: order=0.087___
between O2 and O3: order=-0.172___ between O2 and O4: order=-0.110___
between O2 and O5: order=0.566___ between O3 and O4: order=-0.171___
between O4 and O5: order=-0.066___

## 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 C1-O2 with 1.9921 electrons
__has 33.09% C 1 character in a sp2.47 hybrid
__has 66.91% O 2 character in a sp2.61 hybrid

2. A bonding orbital for C1-O3 with 1.9939 electrons
__has 35.98% C 1 character in a sp1.84 hybrid
__has 64.02% O 3 character in a sp2.12 hybrid

3. A bonding orbital for C1-O4 with 1.9979 electrons
__has 35.76% C 1 character in a sp1.75 hybrid
__has 64.24% O 4 character in a sp1.91 hybrid

4. A bonding orbital for C1-O4 with 1.9979 electrons
__has 16.91% C 1 character in a p-pi orbital ( 99.16% p 0.84% d)
__has 83.09% O 4 character in a p-pi orbital ( 99.90% p 0.10% d)

5. A bonding orbital for O2-O5 with 1.9876 electrons
__has 65.30% O 2 character in a s0.68 p3 hybrid
__has 34.70% O 5 character in a s0.21 p3 hybrid

11. A lone pair orbital for O2 with 1.9791 electrons

12. A lone pair orbital for O2 with 1.8841 electrons
__made from a p-pi orbital ( 99.96% p)

13. A lone pair orbital for O3 with 1.9798 electrons

14. A lone pair orbital for O3 with 1.9214 electrons

15. A lone pair orbital for O3 with 1.7629 electrons

16. A lone pair orbital for O4 with 1.9776 electrons

17. A lone pair orbital for O4 with 1.9095 electrons

18. A lone pair orbital for O5 with 1.9986 electrons

19. A lone pair orbital for O5 with 1.9932 electrons
__made from a p-pi orbital (100.00% p)

20. A lone pair orbital for O5 with 1.9878 electrons
__made from a s0.40 p3 hybrid

116. A antibonding orbital for C1-O2 with 0.1027 electrons
__has 66.91% C 1 character in a sp2.47 hybrid
__has 33.09% O 2 character in a sp2.61 hybrid

119. A antibonding orbital for C1-O4 with 0.3393 electrons
__has 83.09% C 1 character in a p-pi orbital ( 99.16% p 0.84% d)
__has 16.91% O 4 character in a p-pi orbital ( 99.90% p 0.10% d)

-With core pairs on: C 1 O 2 O 3 O 4 O 5 -

#### 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 bonding donor orbital, 5, for O2-O5 with the antibonding acceptor orbital, 117, for C1-O3 is 22.1 kJ/mol.

The interaction of lone pair donor orbital, 11, for O2 with the antibonding acceptor orbital, 118, for C1-O4 is 43.7 kJ/mol.

The interaction of the second lone pair donor orbital, 12, for O2 with the second antibonding acceptor orbital, 119, for C1-O4 is 222. kJ/mol.

The interaction of lone pair donor orbital, 13, for O3 with the antibonding acceptor orbital, 118, for C1-O4 is 22.1 kJ/mol.

The interaction of the second lone pair donor orbital, 14, for O3 with the antibonding acceptor orbital, 116, for C1-O2 is 103. kJ/mol.

The interaction of the second lone pair donor orbital, 14, for O3 with the antibonding acceptor orbital, 118, for C1-O4 is 84.0 kJ/mol.

The interaction of the third lone pair donor orbital, 15, for O3 with the second antibonding acceptor orbital, 119, for C1-O4 is 493. kJ/mol.

The interaction of lone pair donor orbital, 16, for O4 with the antibonding acceptor orbital, 117, for C1-O3 is 23.5 kJ/mol.

The interaction of the second lone pair donor orbital, 17, for O4 with the antibonding acceptor orbital, 116, for C1-O2 is 136. kJ/mol.

The interaction of the second lone pair donor orbital, 17, for O4 with the antibonding acceptor orbital, 117, for C1-O3 is 92.5 kJ/mol.

The interaction of the third lone pair donor orbital, 20, for O5 with the antibonding acceptor orbital, 116, for C1-O2 is 24.8 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.

24 ----- 14.02
23 ----- 13.34

22 ----- 11.28
21 ----- 10.34

20 -^-v- 6.847
19 -^-v- 6.501

18 -^-v- 5.285

17 -^-v- 4.388
16 -^-v- 4.061

15 -^-v- 3.328

14 -^-v- 2.233

13 -^-v- 0.294
12 -^-v- 0.286

11 -^-v- -0.133

10 -^-v- -1.614

9 -^-v- -8.326

8 -^-v- -12.44

7 -^-v- -13.35

6 -^-v- -15.60

5 -^-v- -258.7

4 -^-v- -493.7

3 -^-v- -494.4 2 -^-v- -494.4

1 -^-v- -496.4

## 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 = -338.9758674730 Hartrees