## CH3NH3+, methylphosphonium ion

 H3 H8 H7 \ | / H5 - C1 - P2 / \ H4 H6
The ion charge is 1.

## Atomic Charges and Dipole Moment

C1 charge=-0.420
P2 charge= 0.345
H3 charge= 0.209
H4 charge= 0.210
H5 charge= 0.209
H6 charge= 0.148
H7 charge= 0.148
H8 charge= 0.148
with a dipole moment of 0.56470 Debye

## Bond Lengths:

between C1 and P2: distance=1.821 ang___ between C1 and H3: distance=1.103 ang___
between C1 and H4: distance=1.103 ang___ between C1 and H5: distance=1.104 ang___
between P2 and H6: distance=1.422 ang___ between P2 and H7: distance=1.422 ang___
between P2 and H8: distance=1.421 ang___

## Bond Angles:

for H3-C1-P2: angle=109.0 deg___ for H4-C1-P2: angle=109.2 deg___
for H5-C1-P2: angle=109.0 deg___ for H6-P2-C1: angle=112.1 deg___
for H7-P2-C1: angle=112.1 deg___ for H8-P2-C1: angle=112.0 deg___

## Bond Orders (Mulliken):

between C1 and P2: order=0.943___ between C1 and H3: order=0.917___
between C1 and H4: order=0.917___ between C1 and H5: order=0.917___
between P2 and H6: order=0.935___ between P2 and H7: order=0.935___
between P2 and H8: order=0.935___

## 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 C1-P2 with 1.9907 electrons
__has 54.89% C 1 character in a s0.92 p3 hybrid
__has 45.11% P 2 character in a sp2.40 hybrid

2. A bonding orbital for C1-H3 with 1.9876 electrons
__has 63.34% C 1 character in a sp2.91 hybrid
__has 36.66% H 3 character in a s orbital

3. A bonding orbital for C1-H4 with 1.9877 electrons
__has 63.36% C 1 character in a sp2.90 hybrid
__has 36.64% H 4 character in a s orbital

4. A bonding orbital for C1-H5 with 1.9876 electrons
__has 63.34% C 1 character in a sp2.91 hybrid
__has 36.66% H 5 character in a s orbital

5. A bonding orbital for P2-H6 with 1.9867 electrons
__has 53.17% P 2 character in a s0.94 p3 hybrid
__has 46.83% H 6 character in a s orbital

6. A bonding orbital for P2-H7 with 1.9867 electrons
__has 53.17% P 2 character in a s0.94 p3 hybrid
__has 46.83% H 7 character in a s orbital

7. A bonding orbital for P2-H8 with 1.9867 electrons
__has 53.16% P 2 character in a s0.94 p3 hybrid
__has 46.84% H 8 character in a s orbital

-With core pairs on: C 1 P 2 P 2 P 2 P 2 P 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.

## 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.

17 ----- -5.380

16 ----- -5.922
15 ----- -5.935

14 ----- -6.349

13 -^-v- -15.49 12 -^-v- -15.49

11 -^-v- -15.92

10 -^-v- -17.30 9 -^-v- -17.30

8 -^-v- -21.86

7 -^-v- -24.94

6 -^-v- -130.9
5 -^-v- -131.0 4 -^-v- -131.0

3 -^-v- -178.5

2 -^-v- -272.6

1 -^-v- -2075.

## 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 = -382.8365883610 Hartrees