H9 H8 \ | C3 H7 / \ / O1 = C2 C4 | \ H6 H5
The multiplicity is 2.

## Atomic Charges and Dipole Moment

O1 charge=-0.222
C2 charge=-0.034
C3 charge= 0.371
C4 charge=-0.657
H5 charge= 0.153
H6 charge= 0.182
H7 charge= 0.158
H8 charge= 0.032
H9 charge= 0.015
with a dipole moment of 2.75813 Debye

## Bond Lengths:

between O1 and C2: distance=1.201 ang___ between O1 and C3: distance=2.453 ang___
between C2 and C3: distance=1.523 ang___ between C2 and C4: distance=2.558 ang___
between C3 and C4: distance=1.536 ang___ between C3 and H8: distance=1.109 ang___
between C3 and H9: distance=1.109 ang___ between C4 and H5: distance=1.103 ang___
between C4 and H6: distance=1.103 ang___ between C4 and H7: distance=1.103 ang___

## Bond Angles:

for C3-C2-O1: angle=128.1 deg___ for C4-C3-C2: angle=113.4 deg___
for H5-C4-C3: angle=110.8 deg___ for H6-C4-C3: angle=110.8 deg___
for H7-C4-C3: angle=110.8 deg___ for H8-C3-C2: angle=105.0 deg___
for H9-C3-C2: angle=107.6 deg___

## Bond Orders (Mulliken):

between O1 and C2: order=1.996___ between O1 and C3: order=-0.065___
between C2 and C3: order=0.652___ between C2 and C4: order=0.059___
between C3 and C4: order=0.785___ between C3 and H8: order=0.961___
between C3 and H9: order=0.973___ between C4 and H5: order=0.979___
between C4 and H6: order=0.980___ between C4 and H7: order=0.982___

## 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 0.9986 electrons
__has 67.94% O 1 character in a sp1.45 hybrid
__has 32.06% C 2 character in a sp2.12 hybrid

2. A bonding orbital for O1-C2 with 0.9978 electrons
__has 72.02% O 1 character in a p3 hybrid
__has 27.98% C 2 character in a p3 hybrid

3. A bonding orbital for C2-C3 with 0.9956 electrons
__has 43.35% C 2 character in a sp2.39 hybrid
__has 56.65% C 3 character in a sp2.81 hybrid

4. A bonding orbital for C3-C4 with 0.9970 electrons
__has 52.31% C 3 character in a sp2.27 hybrid
__has 47.69% C 4 character in a sp2.53 hybrid

5. A bonding orbital for C3-H8 with 0.9872 electrons
__has 60.74% C 3 character in a s0.82 p3 hybrid
__has 39.26% H 8 character in a s orbital

6. A bonding orbital for C3-H9 with 0.9914 electrons
__has 60.33% C 3 character in a s0.85 p3 hybrid
__has 39.67% H 9 character in a s orbital

7. A bonding orbital for C4-H5 with 0.9959 electrons
__has 59.52% C 4 character in a s0.94 p3 hybrid
__has 40.48% H 5 character in a s orbital

8. A bonding orbital for C4-H6 with 0.9960 electrons
__has 59.43% C 4 character in a s0.93 p3 hybrid
__has 40.57% H 6 character in a s orbital

9. A bonding orbital for C4-H7 with 0.9957 electrons
__has 59.66% C 4 character in a s0.95 p3 hybrid
__has 40.34% H 7 character in a s orbital

14. A lone pair orbital for O1 with 0.9930 electrons

15. A lone pair orbital for O1 with 0.9722 electrons
__made from a s0.06 p3 hybrid

16. A lone pair orbital for C2 with 0.9829 electrons

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

#### Up Electrons

1. A bonding orbital for O1-C2 with 0.9990 electrons
__has 66.68% O 1 character in a sp1.58 hybrid
__has 33.32% C 2 character in a sp1.28 hybrid

2. A bonding orbital for O1-C2 with 0.9985 electrons
__has 78.39% O 1 character in a p3 hybrid
__has 21.61% C 2 character in a p3 hybrid

3. A bonding orbital for O1-C2 with 0.9959 electrons
__has 78.29% O 1 character in a s0.13 p3 hybrid
__has 21.71% C 2 character in a p3 hybrid

4. A bonding orbital for C2-C3 with 0.9959 electrons
__has 51.32% C 2 character in a sp0.80 hybrid
__has 48.68% C 3 character in a s0.83 p3 hybrid

5. A bonding orbital for C3-C4 with 0.9972 electrons
__has 51.55% C 3 character in a sp2.37 hybrid
__has 48.45% C 4 character in a sp2.51 hybrid

6. A bonding orbital for C3-H8 with 0.9844 electrons
__has 60.70% C 3 character in a s0.92 p3 hybrid
__has 39.30% H 8 character in a s orbital

7. A bonding orbital for C3-H9 with 0.9861 electrons
__has 61.26% C 3 character in a sp2.95 hybrid
__has 38.74% H 9 character in a s orbital

8. A bonding orbital for C4-H5 with 0.9960 electrons
__has 59.60% C 4 character in a s0.94 p3 hybrid
__has 40.40% H 5 character in a s orbital

9. A bonding orbital for C4-H6 with 0.9959 electrons
__has 59.52% C 4 character in a s0.94 p3 hybrid
__has 40.48% H 6 character in a s orbital

10. A bonding orbital for C4-H7 with 0.9954 electrons
__has 59.48% C 4 character in a s0.94 p3 hybrid
__has 40.52% H 7 character in a s orbital

15. A lone pair orbital for O1 with 0.9913 electrons

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

## 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 ----- 2.595

19 ----- 1.602

18 ----- 1.427

17 ----- -2.294

16 -^--- -4.285

15 -^-v- -8.775

14 -^-v- -9.219

13 -^-v- -9.382

12 -^-v- -10.17

11 -^-v- -10.87

10 -^-v- -11.64

9 -^-v- -11.88

8 -^-v- -13.27

7 -^-v- -16.34

6 -^-v- -19.72

5 -^-v- -27.04

4 -^-v- -266.5

3 -^-v- -267.3

2 -^-v- -268.9

1 -^-v- -507.6

## 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 = -192.5602841947 Hartrees