## CO32-, carbonate ion

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

## Atomic Charges and Dipole Moment

C1 charge= 1.154
O2 charge=-1.051
O3 charge=-1.051
O4 charge=-1.051
with a dipole moment of 0.00256 Debye

## Bond Lengths:

between C1 and O2: distance=1.327 ang___ between C1 and O3: distance=1.327 ang___
between C1 and O4: distance=1.327 ang___ between O2 and O3: distance=2.298 ang___
between O2 and O4: distance=2.298 ang___ between O3 and O4: distance=2.298 ang___

## Bond Angles:

for O3-C1-O2: angle=119.9 deg___ for O4-C1-O2: angle=120.0 deg___

## Bond Orders (Mulliken):

between C1 and O2: order=1.410___ between C1 and O3: order=1.410___
between C1 and O4: order=1.410___ between O2 and O3: order=-0.168___
between O2 and O4: order=-0.168___ between O3 and O4: order=-0.168___

## 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 1.9976 electrons
__has 35.40% C 1 character in a sp1.99 hybrid
__has 64.60% O 2 character in a sp2.24 hybrid

2. A bonding orbital for C1-O3 with 1.9976 electrons
__has 35.40% C 1 character in a sp1.99 hybrid
__has 64.60% O 3 character in a sp2.24 hybrid

3. A bonding orbital for C1-O3 with 1.9981 electrons
__has 12.94% C 1 character in a p-pi orbital ( 99.08% p 0.92% d)
__has 87.06% O 3 character in a p-pi orbital ( 99.93% p)

4. A bonding orbital for C1-O4 with 1.9976 electrons
__has 35.40% C 1 character in a sp1.99 hybrid
__has 64.60% O 4 character in a sp2.24 hybrid

9. A lone pair orbital for O2 with 1.9782 electrons

10. A lone pair orbital for O2 with 1.9401 electrons
__made from a p-pi orbital ( 99.96% p)

11. A lone pair orbital for O2 with 1.7915 electrons
__made from a p-pi orbital ( 99.94% p)

12. A lone pair orbital for O3 with 1.9782 electrons

13. A lone pair orbital for O3 with 1.9400 electrons
__made from a p-pi orbital ( 99.96% p)

14. A lone pair orbital for O4 with 1.9782 electrons

15. A lone pair orbital for O4 with 1.9400 electrons
__made from a p-pi orbital ( 99.96% p)

16. A lone pair orbital for O4 with 1.7914 electrons
__made from a p-pi orbital ( 99.94% p)

95. A antibonding orbital for C1-O3 with 0.4000 electrons
__has 87.06% C 1 character in a p-pi orbital ( 99.08% p 0.92% d)
__has 12.94% O 3 character in a p-pi orbital ( 99.93% p)

-With core pairs on: C 1 O 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, 10, for O2 with the antibonding acceptor orbital, 94, for C1-O3 is 82.0 kJ/mol.

The interaction of the second lone pair donor orbital, 10, for O2 with the antibonding acceptor orbital, 96, for C1-O4 is 82.0 kJ/mol.

The interaction of the third lone pair donor orbital, 11, for O2 with the second antibonding acceptor orbital, 95, for C1-O3 is 430. kJ/mol.

The interaction of the second lone pair donor orbital, 13, for O3 with the antibonding acceptor orbital, 93, for C1-O2 is 82.0 kJ/mol.

The interaction of the second lone pair donor orbital, 13, for O3 with the antibonding acceptor orbital, 96, for C1-O4 is 82.0 kJ/mol.

The interaction of the second lone pair donor orbital, 15, for O4 with the antibonding acceptor orbital, 93, for C1-O2 is 82.0 kJ/mol.

The interaction of the second lone pair donor orbital, 15, for O4 with the antibonding acceptor orbital, 94, for C1-O3 is 82.0 kJ/mol.

The interaction of the third lone pair donor orbital, 16, for O4 with the second antibonding acceptor orbital, 95, for C1-O3 is 431. 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.

20 ----- 15.14
19 ----- 14.90
18 ----- 14.51

17 ----- 12.90

16 -^-v- 7.660

15 -^-v- 6.166 14 -^-v- 6.165
13 -^-v- 5.927 12 -^-v- 5.926

11 -^-v- 2.262
10 -^-v- 2.161 9 -^-v- 2.160

8 -^-v- 0.479

7 -^-v- -10.11 6 -^-v- -10.11

5 -^-v- -13.11

4 -^-v- -257.0

3 -^-v- -492.6 2 -^-v- -492.6 1 -^-v- -492.6

### 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 = -263.7810061477 Hartrees