H8 H3 \ / C1 = C2 // \ H7 - C5 H4 \ H6
The multiplicity is 2.

## Atomic Charges and Dipole Moment

C1 charge= 0.105
C2 charge=-0.497
H3 charge= 0.182
H4 charge= 0.208
C5 charge=-0.500
H6 charge= 0.209
H7 charge= 0.183
H8 charge= 0.109
with a dipole moment of 0.07868 Debye

## Bond Lengths:

between C1 and C2: distance=1.394 ang___ between C1 and H4: distance=2.172 ang___
between C1 and C5: distance=1.394 ang___ between C1 and H6: distance=2.171 ang___
between C1 and H8: distance=1.100 ang___ between C2 and H3: distance=1.093 ang___
between C2 and H4: distance=1.097 ang___ between C2 and C5: distance=2.471 ang___
between C5 and H6: distance=1.097 ang___ between C5 and H7: distance=1.093 ang___

## Bond Angles:

for H3-C2-C1: angle=121.2 deg___ for H4-C2-C1: angle=120.9 deg___
for C5-C1-C2: angle=124.8 deg___ for H6-C5-C1: angle=120.9 deg___
for H7-C5-C1: angle=121.2 deg___ for H8-C1-C2: angle=117.5 deg___

## Bond Orders (Mulliken):

between C1 and C2: order=1.177___ between C1 and H4: order=-0.065___
between C1 and C5: order=1.178___ between C1 and H6: order=-0.066___
between C1 and H8: order=0.923___ between C2 and H3: order=0.972___
between C2 and H4: order=0.982___ between C2 and C5: order=0.240___
between C5 and H6: order=0.982___ between C5 and H7: order=0.972___

## 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.

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 C1-C2 with 0.9967 electrons
__has 49.26% C 1 character in a sp1.75 hybrid
__has 50.74% C 2 character in a sp1.55 hybrid

2. A bonding orbital for C1-C5 with 0.9967 electrons
__has 49.26% C 1 character in a sp1.75 hybrid
__has 50.74% C 5 character in a sp1.55 hybrid

3. A bonding orbital for C1-H8 with 0.9897 electrons
__has 57.83% C 1 character in a sp2.63 hybrid
__has 42.17% H 8 character in a s orbital

4. A bonding orbital for C2-H3 with 0.9946 electrons
__has 60.71% C 2 character in a sp2.26 hybrid
__has 39.29% H 3 character in a s orbital

5. A bonding orbital for C2-H4 with 0.9945 electrons
__has 60.39% C 2 character in a sp2.28 hybrid
__has 39.61% H 4 character in a s orbital

6. A bonding orbital for C5-H6 with 0.9945 electrons
__has 60.39% C 5 character in a sp2.28 hybrid
__has 39.61% H 6 character in a s orbital

7. A bonding orbital for C5-H7 with 0.9946 electrons
__has 60.71% C 5 character in a sp2.26 hybrid
__has 39.29% H 7 character in a s orbital

11. A lone pair orbital for C1 with 0.2812 electrons
__made from a p-pi orbital ( 99.93% p 0.07% d)

12. A lone pair orbital for C2 with 0.8578 electrons
__made from a p-pi orbital ( 99.98% p)

13. A lone pair orbital for C5 with 0.8577 electrons
__made from a p-pi orbital ( 99.98% p)

-With core pairs on: C 1 C 2 C 5 -

#### Up Electrons

1. A bonding orbital for C1-C2 with 0.9963 electrons
__has 54.14% C 1 character in a sp1.72 hybrid
__has 45.86% C 2 character in a sp1.61 hybrid

2. A bonding orbital for C1-C2 with 0.8635 electrons
__has 84.22% C 1 character in a p-pi orbital ( 99.97% p)
__has 15.78% C 2 character in a p-pi orbital ( 99.78% p 0.22% d)

3. A bonding orbital for C1-C5 with 0.9963 electrons
__has 54.14% C 1 character in a sp1.72 hybrid
__has 45.86% C 5 character in a sp1.61 hybrid

4. A bonding orbital for C1-H8 with 0.9890 electrons
__has 60.78% C 1 character in a sp2.74 hybrid
__has 39.22% H 8 character in a s orbital

5. A bonding orbital for C2-H3 with 0.9953 electrons
__has 56.36% C 2 character in a sp2.23 hybrid
__has 43.64% H 3 character in a s orbital

6. A bonding orbital for C2-H4 with 0.9951 electrons
__has 56.14% C 2 character in a sp2.24 hybrid
__has 43.86% H 4 character in a s orbital

7. A bonding orbital for C5-H6 with 0.9951 electrons
__has 56.14% C 5 character in a sp2.24 hybrid
__has 43.86% H 6 character in a s orbital

8. A bonding orbital for C5-H7 with 0.9953 electrons
__has 56.36% C 5 character in a sp2.23 hybrid
__has 43.64% H 7 character in a s orbital

12. A lone pair orbital for C5 with 0.1363 electrons
__made from a p-pi orbital ( 99.78% p 0.22% d)

-With core pairs on: C 1 C 2 C 5 -

#### 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, 2, for C1-C2 with the lone pair acceptor orbital, 12, for C5 is 265. 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. Only the spin up electron orbital energies are given.

16 ----- 2.278

15 ----- 2.046
14 ----- 1.958

13 ----- -0.461

12 -^--- -4.703

11 -^-v- -7.975

10 -^-v- -8.687

9 -^-v- -9.367

8 -^-v- -10.73

7 -^-v- -11.78

6 -^-v- -13.59

5 -^-v- -16.63

4 -^-v- -19.56

3 -^-v- -266.6 2 -^-v- -266.6
1 -^-v- -266.6

## 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 = -117.2936682002 Hartrees