O3 // O1 = C2 \\ O4
The ion charge is -1. The multiplicity is 2.

## Atomic Charges and Dipole Moment

O1 charge=-0.638
C2 charge= 0.912
O3 charge=-0.636
O4 charge=-0.637
with a dipole moment of 6.12595 Debye

## Bond Lengths:

between O1 and C2: distance=1.291 ang___ between C2 and O3: distance=1.291 ang___
between C2 and O4: distance=1.291 ang___

## Bond Angles:

for O3-C2-O1: angle=119.9 deg___ for O4-C2-O1: angle=120.0 deg___

## Bond Orders (Mulliken):

between O1 and C2: order=1.542___ between C2 and O3: order=1.543___
between C2 and O4: order=1.542___

## 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. The Lewis structure is built for the up and down electrons, separately. Note that the up and down structures can be very different.

### Hybridization in the Best Lewis Structure

#### Down Electrons

1. A bonding orbital for O1-C2 with 0.9992 electrons
__has 65.42% O 1 character in a sp2.17 hybrid
__has 34.58% C 2 character in a sp1.99 hybrid

2. A bonding orbital for C2-O3 with 0.9992 electrons
__has 34.59% C 2 character in a sp1.99 hybrid
__has 65.41% O 3 character in a sp2.17 hybrid

3. A bonding orbital for C2-O4 with 0.9992 electrons
__has 34.58% C 2 character in a sp1.99 hybrid
__has 65.42% O 4 character in a sp2.17 hybrid

8. A lone pair orbital for O1 with 0.9908 electrons

9. A lone pair orbital for O1 with 0.9735 electrons
__made from a p-pi orbital ( 99.94% p 0.06% d)

10. A lone pair orbital for O1 with 0.9024 electrons
__made from a p-pi orbital ( 99.91% p 0.09% d)

11. A lone pair orbital for C2 with 0.2865 electrons
__made from a p-pi orbital (100.00% p)

12. A lone pair orbital for O3 with 0.9908 electrons

13. A lone pair orbital for O3 with 0.9734 electrons
__made from a p-pi orbital ( 99.94% p 0.06% d)

14. A lone pair orbital for O3 with 0.9022 electrons
__made from a p-pi orbital ( 99.91% p 0.09% d)

15. A lone pair orbital for O4 with 0.9908 electrons

16. A lone pair orbital for O4 with 0.9735 electrons
__made from a p-pi orbital ( 99.94% p 0.06% d)

17. A lone pair orbital for O4 with 0.9024 electrons
__made from a p-pi orbital ( 99.91% p 0.09% d)

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

#### Up Electrons

1. A bonding orbital for O1-C2 with 0.9987 electrons
__has 63.89% O 1 character in a sp2.08 hybrid
__has 36.11% C 2 character in a sp1.99 hybrid

2. A antibonding orbital for O1-O4 with 0.9973 electrons
__has 50.00% O 1 character in a p-pi orbital ( 99.92% p 0.08% d)
__has 50.00% O 4 character in a p-pi orbital ( 99.92% p 0.08% d)

3. A bonding orbital for O1-O4 with 0.7827 electrons
__has 50.00% O 1 character in a p-pi orbital ( 99.92% p 0.08% d)
__has 50.00% O 4 character in a p-pi orbital ( 99.92% p 0.08% d)

4. A bonding orbital for C2-O3 with 0.9991 electrons
__has 13.80% C 2 character in a p-pi orbital ( 98.90% p 1.10% d)
__has 86.20% O 3 character in a p-pi orbital ( 99.91% p 0.09% d)

5. A bonding orbital for C2-O3 with 0.9939 electrons
__has 36.03% C 2 character in a sp1.99 hybrid
__has 63.97% O 3 character in a sp2.15 hybrid

6. A bonding orbital for C2-O4 with 0.9938 electrons
__has 36.02% C 2 character in a sp1.99 hybrid
__has 63.98% O 4 character in a sp2.15 hybrid

7. A bonding orbital for O3-O4 with 0.9344 electrons
__has 50.12% O 3 character in a p3 hybrid
__has 49.88% O 4 character in a p3 hybrid

12. A lone pair orbital for O1 with 0.9899 electrons

13. A lone pair orbital for O1 with 0.6097 electrons
__made from a p-pi orbital ( 99.91% p 0.09% d)

14. A lone pair orbital for O3 with 0.9899 electrons

15. A lone pair orbital for O4 with 0.9899 electrons

93. A antibonding orbital for C2-O3 with 0.2091 electrons
__has 86.20% C 2 character in a p-pi orbital ( 98.90% p 1.10% d)
__has 13.80% O 3 character in a p-pi orbital ( 99.91% p 0.09% d)

96. A antibonding orbital for O3-O4 with 0.2876 electrons
__has 49.88% O 3 character in a p3 hybrid
__has 50.12% O 4 character in a p3 hybrid

-With core pairs on: O 1 C 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 bonding donor orbital, 3, for O1-O4 with the antibonding acceptor orbital, 93, for C2-O3 is 551. kJ/mol.

The interaction of the second bonding donor orbital, 5, for C2-O3 with the antibonding acceptor orbital, 96, for O3-O4 is 23.1 kJ/mol.

The interaction of bonding donor orbital, 6, for C2-O4 with the antibonding acceptor orbital, 96, for O3-O4 is 23.3 kJ/mol.

The interaction of bonding donor orbital, 7, for O3-O4 with the antibonding acceptor orbital, 92, for O1-C2 is 116. kJ/mol.

The interaction of the second lone pair donor orbital, 13, for O1 with the second antibonding acceptor orbital, 94, for C2-O3 is 52.8 kJ/mol.

The interaction of the second lone pair donor orbital, 13, for O1 with the antibonding acceptor orbital, 95, for C2-O4 is 52.8 kJ/mol.

The interaction of the second lone pair donor orbital, 13, for O1 with the antibonding acceptor orbital, 96, for O3-O4 is 326. kJ/mol.

The interaction of antibonding donor orbital, 96, for O3-O4 with the second antibonding acceptor orbital, 94, for C2-O3 is 28.6 kJ/mol.

The interaction of antibonding donor orbital, 96, for O3-O4 with the antibonding acceptor orbital, 95, for C2-O4 is 28.6 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. Only the spin up electron orbital energies are given.

20 ----- 9.597
19 ----- 9.339
18 ----- 8.539

17 ----- 6.012

16 -^--- -0.625

15 -^-v- -1.457 14 -^-v- -1.458

13 -^-v- -2.183 12 -^-v- -2.186

11 -^-v- -5.484

10 -^-v- -5.683 9 -^-v- -5.684

8 -^-v- -7.029

7 -^-v- -18.45 6 -^-v- -18.46

5 -^-v- -21.60

4 -^-v- -264.3

3 -^-v- -500.9 2 -^-v- -500.9 1 -^-v- -500.9

## 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 = -263.9356612035 Hartrees