## Nitrate ion, NO3-

 O3 \ N1 - O2 / O4
The ion charge is -1.

## Atomic Charges and Dipole Moment

N1 charge= 0.952
O2 charge=-0.650
O3 charge=-0.651
O4 charge=-0.651
with a dipole moment of 0.00140 Debye

## Bond Lengths:

between N1 and O2: distance=1.282 ang___ between N1 and O3: distance=1.282 ang___
between N1 and O4: distance=1.282 ang___ between O2 and O3: distance=2.220 ang___
between O2 and O4: distance=2.221 ang___ between O3 and O4: distance=2.220 ang___

## Bond Angles:

for O3-N1-O2: angle=119.9 deg___ for O4-N1-O2: angle=120.0 deg___

## Bond Orders (Mulliken):

between N1 and O2: order=1.368___ between N1 and O3: order=1.368___
between N1 and O4: order=1.368___ between O2 and O3: order=-0.110___
between O2 and O4: order=-0.110___ between O3 and O4: order=-0.110___

## 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 N1-O2 with 1.9962 electrons
__has 51.85% N 1 character in a sp1.99 hybrid
__has 48.15% O 2 character in a s0.70 p3 hybrid

2. A bonding orbital for N1-O3 with 1.9962 electrons
__has 51.84% N 1 character in a sp1.99 hybrid
__has 48.16% O 3 character in a s0.70 p3 hybrid

3. A bonding orbital for N1-O3 with 1.9980 electrons
__has 23.87% N 1 character in a p-pi orbital ( 99.56% p 0.44% d)
__has 76.13% O 3 character in a p-pi orbital ( 99.90% p 0.10% d)

4. A bonding orbital for N1-O4 with 1.9962 electrons
__has 51.84% N 1 character in a sp1.99 hybrid
__has 48.16% O 4 character in a s0.70 p3 hybrid

5. A antibonding orbital for O2-O4 with 1.9958 electrons
__has 50.01% O 2 character in a p-pi orbital ( 99.92% p 0.08% d)
__has 49.99% O 4 character in a p-pi orbital ( 99.92% p 0.08% d)

6. A bonding orbital for O2-O4 with 1.3505 electrons
__has 49.99% O 2 character in a p-pi orbital ( 99.92% p 0.08% d)
__has 50.01% O 4 character in a p-pi orbital ( 99.92% p 0.08% d)

11. A lone pair orbital for O2 with 1.9835 electrons

12. A lone pair orbital for O2 with 1.9430 electrons
__made from a p-pi orbital ( 99.95% p)

13. A lone pair orbital for O3 with 1.9835 electrons

14. A lone pair orbital for O3 with 1.9430 electrons
__made from a p-pi orbital ( 99.95% p)

15. A lone pair orbital for O4 with 1.9835 electrons

16. A lone pair orbital for O4 with 1.9430 electrons
__made from a p-pi orbital ( 99.95% p)

95. A antibonding orbital for N1-O3 with 0.6373 electrons
__has 76.13% N 1 character in a p-pi orbital ( 99.56% p 0.44% d)
__has 23.87% O 3 character in a p-pi orbital ( 99.90% p 0.10% d)

-With core pairs on: N 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 bonding donor orbital, 3, for N1-O3 with the bonding acceptor orbital, 6, for O2-O4 is 84.9 kJ/mol.

The interaction of the second bonding donor orbital, 3, for N1-O3 with the second antibonding acceptor orbital, 95, for N1-O3 is 35.9 kJ/mol.

The interaction of bonding donor orbital, 6, for O2-O4 with the second antibonding acceptor orbital, 95, for N1-O3 is 2013 kJ/mol.

The interaction of the second lone pair donor orbital, 12, for O2 with the antibonding acceptor orbital, 94, for N1-O3 is 74.3 kJ/mol.

The interaction of the second lone pair donor orbital, 12, for O2 with the antibonding acceptor orbital, 96, for N1-O4 is 74.3 kJ/mol.

The interaction of the second lone pair donor orbital, 14, for O3 with the antibonding acceptor orbital, 93, for N1-O2 is 74.3 kJ/mol.

The interaction of the second lone pair donor orbital, 14, for O3 with the antibonding acceptor orbital, 96, for N1-O4 is 74.3 kJ/mol.

The interaction of the second lone pair donor orbital, 16, for O4 with the antibonding acceptor orbital, 93, for N1-O2 is 74.3 kJ/mol.

The interaction of the second lone pair donor orbital, 16, for O4 with the antibonding acceptor orbital, 94, for N1-O3 is 74.3 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 ----- 10.66 19 ----- 10.66

18 ----- 8.385

17 ----- 3.583

16 -^-v- 0.322

15 -^-v- -1.343 14 -^-v- -1.343

13 -^-v- -1.603 12 -^-v- -1.604

11 -^-v- -6.570 10 -^-v- -6.571

9 -^-v- -7.228

8 -^-v- -8.715

7 -^-v- -19.19 6 -^-v- -19.19

5 -^-v- -24.61

4 -^-v- -378.0

3 -^-v- -500.7 2 -^-v- -500.7 1 -^-v- -500.7

## 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 = -280.4993456103 Hartrees