## H3N+-OH, hydroxyl ammonium ion

 H3 | H5 - N1 - O2 / \ H4 H6
The ion charge is 1.

## Atomic Charges and Dipole Moment

N1 charge=-0.358
O2 charge=-0.346
H3 charge= 0.445
H4 charge= 0.391
H5 charge= 0.391
H6 charge= 0.476
with a dipole moment of 3.99444 Debye

## Bond Lengths:

between N1 and O2: distance=1.427 ang___ between N1 and H3: distance=1.041 ang___
between N1 and H4: distance=1.042 ang___ between N1 and H5: distance=1.042 ang___
between O2 and H6: distance=0.988 ang___

## Bond Angles:

for H3-N1-O2: angle=104.2 deg___ for H4-N1-O2: angle=111.8 deg___
for H5-N1-O2: angle=111.9 deg___ for H6-O2-N1: angle=107.0 deg___

## Bond Orders (Mulliken):

between N1 and O2: order=0.849___ between N1 and H3: order=0.815___
between N1 and H4: order=0.818___ between N1 and H5: order=0.819___
between O2 and H6: order=0.824___

## 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.

### Hybridization in the Best Lewis Structure

1. A bonding orbital for N1-O2 with 1.9970 electrons
__has 51.57% N 1 character in a s0.91 p3 hybrid
__has 48.43% O 2 character in a s0.53 p3 hybrid

2. A bonding orbital for N1-H3 with 1.9968 electrons
__has 73.43% N 1 character in a sp2.98 hybrid
__has 26.57% H 3 character in a s orbital

3. A bonding orbital for N1-H4 with 1.9977 electrons
__has 72.68% N 1 character in a sp2.85 hybrid
__has 27.32% H 4 character in a s orbital

4. A bonding orbital for N1-H5 with 1.9977 electrons
__has 72.68% N 1 character in a sp2.85 hybrid
__has 27.32% H 5 character in a s orbital

5. A bonding orbital for O2-H6 with 1.9925 electrons
__has 75.59% O 2 character in a s0.87 p3 hybrid
__has 24.41% H 6 character in a s orbital

8. A lone pair orbital for O2 with 1.9928 electrons

9. A lone pair orbital for O2 with 1.9812 electrons
__made from a p-pi orbital ( 99.94% p 0.06% d)

-With core pairs on: N 1 O 2 -

#### 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, 9, for O2 with the antibonding acceptor orbital, 70, for N1-H4 is 21.2 kJ/mol.

The interaction of the second lone pair donor orbital, 9, for O2 with the antibonding acceptor orbital, 71, for N1-H5 is 21.0 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.

13 ----- -4.536
12 ----- -4.575

11 ----- -6.478

10 ----- -7.627

9 -^-v- -14.35

8 -^-v- -16.51

7 -^-v- -20.73

6 -^-v- -21.67

5 -^-v- -22.25

4 -^-v- -29.19

3 -^-v- -34.90

2 -^-v- -388.7

1 -^-v- -514.9

## 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 = -132.0992892059 Hartrees