H3 H8 O7 \ | / H5 - C1 - C2 / \ H4 H6
The multiplicity is 2.

## Atomic Charges and Dipole Moment

C1 charge=-0.511
C2 charge= 0.594
H3 charge= 0.140
H4 charge= 0.140
H5 charge= 0.098
H6 charge=-0.007
O7 charge=-0.448
H8 charge=-0.006
with a dipole moment of 2.61794 Debye

## Bond Lengths:

between C1 and C2: distance=1.535 ang___ between C1 and H3: distance=1.103 ang___
between C1 and H4: distance=1.103 ang___ between C1 and H5: distance=1.105 ang___
between C1 and O7: distance=2.475 ang___ between C2 and H6: distance=1.130 ang___
between C2 and O7: distance=1.358 ang___ between C2 and H8: distance=1.130 ang___

## Bond Angles:

for H3-C1-C2: angle=110.3 deg___ for H4-C1-C2: angle=110.2 deg___
for H5-C1-C2: angle=111.0 deg___ for H6-C2-C1: angle=111.6 deg___
for O7-C2-C1: angle=117.5 deg___ for H8-C2-C1: angle=111.5 deg___

## Bond Orders (Mulliken):

between C1 and C2: order=0.828___ between C1 and H3: order=0.977___
between C1 and H4: order=0.977___ between C1 and H5: order=0.975___
between C1 and O7: order=-0.050___ between C2 and H6: order=0.987___
between C2 and O7: order=0.903___ between C2 and H8: order=0.986___

## 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 C1-C2 with 0.9987 electrons
__has 49.72% C 1 character in a sp2.60 hybrid
__has 50.28% C 2 character in a sp2.10 hybrid

2. A bonding orbital for C1-H3 with 0.9957 electrons
__has 59.50% C 1 character in a s0.95 p3 hybrid
__has 40.50% H 3 character in a s orbital

3. A bonding orbital for C1-H4 with 0.9957 electrons
__has 59.50% C 1 character in a s0.95 p3 hybrid
__has 40.50% H 4 character in a s orbital

4. A bonding orbital for C1-H5 with 0.9947 electrons
__has 59.40% C 1 character in a s0.96 p3 hybrid
__has 40.60% H 5 character in a s orbital

5. A bonding orbital for C2-H6 with 0.9954 electrons
__has 56.06% C 2 character in a s0.82 p3 hybrid
__has 43.94% H 6 character in a s orbital

6. A bonding orbital for C2-O7 with 0.9989 electrons
__has 34.10% C 2 character in a sp2.97 hybrid
__has 65.90% O 7 character in a sp2.34 hybrid

7. A bonding orbital for C2-H8 with 0.9954 electrons
__has 56.04% C 2 character in a s0.82 p3 hybrid
__has 43.96% H 8 character in a s orbital

11. A lone pair orbital for O7 with 0.9959 electrons

12. A lone pair orbital for O7 with 0.9825 electrons
__made from a p-pi orbital ( 99.96% p)

13. A lone pair orbital for O7 with 0.9772 electrons

-With core pairs on: C 1 C 2 O 7 -

#### Up Electrons

1. A bonding orbital for C1-C2 with 0.9986 electrons
__has 49.55% C 1 character in a sp2.60 hybrid
__has 50.45% C 2 character in a sp2.15 hybrid

2. A bonding orbital for C1-H3 with 0.9961 electrons
__has 59.46% C 1 character in a s0.95 p3 hybrid
__has 40.54% H 3 character in a s orbital

3. A bonding orbital for C1-H4 with 0.9961 electrons
__has 59.47% C 1 character in a s0.95 p3 hybrid
__has 40.53% H 4 character in a s orbital

4. A bonding orbital for C1-H5 with 0.9952 electrons
__has 59.24% C 1 character in a s0.95 p3 hybrid
__has 40.76% H 5 character in a s orbital

5. A bonding orbital for C2-H6 with 0.9735 electrons
__has 61.15% C 2 character in a s0.83 p3 hybrid
__has 38.85% H 6 character in a s orbital

6. A bonding orbital for C2-O7 with 0.9988 electrons
__has 38.53% C 2 character in a sp2.90 hybrid
__has 61.47% O 7 character in a sp2.12 hybrid

7. A bonding orbital for C2-H8 with 0.9732 electrons
__has 61.18% C 2 character in a s0.82 p3 hybrid
__has 38.82% H 8 character in a s orbital

11. A lone pair orbital for O7 with 0.9954 electrons

12. A lone pair orbital for O7 with 0.9730 electrons

-With core pairs on: C 1 C 2 O 7 -

#### 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 bonding donor orbital, 5, for C2-H6 with the third lone pair acceptor orbital, 13, for O7 is 37.0 kJ/mol.

The interaction of bonding donor orbital, 7, for C2-H8 with the third lone pair acceptor orbital, 13, for O7 is 37.6 kJ/mol.

The interaction of the second lone pair donor orbital, 12, for O7 with the antibonding acceptor orbital, 96, for C1-C2 is 37.1 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.

17 ----- 2.626

16 ----- 2.339

15 ----- 1.822

14 ----- 1.396

13 -^--- -6.401

12 -^-v- -7.110

11 -^-v- -9.392
10 -^-v- -9.421

9 -^-v- -10.41

8 -^-v- -11.30

7 -^-v- -12.08

6 -^-v- -15.14

5 -^-v- -18.38

4 -^-v- -25.24

3 -^-v- -266.3

2 -^-v- -268.1

1 -^-v- -507.2

## 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 = -154.4243750256 Hartrees