## CH3COOH rotamer, acetic acid (*see note)

 H3 O8 | // H5 - C1 - C2 - O7 - H6 / H4
Tell me about the atomic charges, dipole moment, bond lengths, angles, bond orders,
molecular orbital energies, or total energy.
Tell me about the best Lewis structure.

## Atomic Charges and Dipole Moment

C1 charge=-0.566
C2 charge= 0.759
H3 charge= 0.177
H4 charge= 0.179
H5 charge= 0.173
H6 charge= 0.418
O7 charge=-0.587
O8 charge=-0.553
with a dipole moment of 1.68571 Debye

## Bond Lengths:

between C1 and C2: distance=1.511 ang___ between C1 and H3: distance=1.104 ang___
between C1 and H4: distance=1.099 ang___ between C1 and H5: distance=1.101 ang___
between C1 and O7: distance=2.400 ang___ between C2 and O7: distance=1.376 ang___
between C2 and O8: distance=1.223 ang___ between H6 and O7: distance=0.984 ang___
between O7 and O8: distance=2.274 ang___

## Bond Angles:

for H3-C1-C2: angle=108.3 deg___ for H4-C1-C2: angle=112.0 deg___
for H5-C1-C2: angle=109.2 deg___ for H6-C2-C1: angle=142.3 deg___
for O7-C2-C1: angle=112.4 deg___ for O8-C2-C1: angle=125.6 deg___

## Bond Orders (Mulliken):

between C1 and C2: order=0.797___ between C1 and H3: order=0.970___
between C1 and H4: order=0.988___ between C1 and H5: order=0.983___
between C1 and O7: order=-0.083___ between C2 and O7: order=1.130___
between C2 and O8: order=1.876___ between H6 and O7: order=0.843___
between O7 and O8: order=-0.169___

## 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.

### Hybridization in the Best Lewis Structure

1. A bonding orbital for C1-C2 with 1.9899 electrons
__has 50.51% C 1 character in a sp2.91 hybrid
__has 49.49% C 2 character in a sp1.67 hybrid

2. A bonding orbital for C1-H3 with 1.9773 electrons
__has 60.94% C 1 character in a s0.95 p3 hybrid
__has 39.06% H 3 character in a s orbital

3. A bonding orbital for C1-H4 with 1.9908 electrons
__has 60.76% C 1 character in a sp2.89 hybrid
__has 39.24% H 4 character in a s orbital

4. A bonding orbital for C1-H5 with 1.9849 electrons
__has 60.99% C 1 character in a s0.99 p3 hybrid
__has 39.01% H 5 character in a s orbital

5. A bonding orbital for C2-O7 with 1.9962 electrons
__has 32.28% C 2 character in a sp2.59 hybrid
__has 67.72% O 7 character in a sp2.29 hybrid

6. A bonding orbital for C2-O8 with 1.9979 electrons
__has 35.56% C 2 character in a sp1.85 hybrid
__has 64.44% O 8 character in a sp1.57 hybrid

7. A bonding orbital for C2-O8 with 1.9958 electrons
__has 25.99% C 2 character in a p3 hybrid
__has 74.01% O 8 character in a p3 hybrid

8. A bonding orbital for H6-O7 with 1.9886 electrons
__has 24.90% H 6 character in a s orbital
__has 75.10% O 7 character in a s0.84 p3 hybrid

13. A lone pair orbital for O7 with 1.9822 electrons
__made from a sp1.09 hybrid

14. A lone pair orbital for O7 with 1.8792 electrons
__made from a p-pi orbital ( 99.94% p 0.06% d)

15. A lone pair orbital for O8 with 1.9770 electrons
__made from a sp0.63 hybrid

16. A lone pair orbital for O8 with 1.8840 electrons
__made from a p-pi orbital ( 99.90% p 0.10% d)

119. A antibonding orbital for C2-O8 with 0.1433 electrons
__has 74.01% C 2 character in a p3 hybrid
__has 25.99% O 8 character in a p3 hybrid

-With core pairs on: C 1 C 2 O 7 O 8 -

#### 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, 2, for C1-H3 with the second antibonding acceptor orbital, 119, for C2-O8 is 33.7 kJ/mol.

The interaction of bonding donor orbital, 3, for C1-H4 with the antibonding acceptor orbital, 118, for C2-O8 is 21.4 kJ/mol.

The interaction of bonding donor orbital, 8, for H6-O7 with the antibonding acceptor orbital, 113, for C1-C2 is 24.3 kJ/mol.

The interaction of lone pair donor orbital, 13, for O7 with the antibonding acceptor orbital, 118, for C2-O8 is 39.1 kJ/mol.

The interaction of the second lone pair donor orbital, 14, for O7 with the second antibonding acceptor orbital, 119, for C2-O8 is 232. kJ/mol.

The interaction of the second lone pair donor orbital, 16, for O8 with the antibonding acceptor orbital, 113, for C1-C2 is 100. kJ/mol.

The interaction of the second lone pair donor orbital, 16, for O8 with the antibonding acceptor orbital, 117, for C2-O7 is 181. 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.

20 ----- 2.544

19 ----- 1.892

18 ----- 0.778

17 ----- -1.440

16 -^-v- -6.699

15 -^-v- -7.977

14 -^-v- -9.674
13 -^-v- -9.738

12 -^-v- -10.11

11 -^-v- -11.69
10 -^-v- -11.76

9 -^-v- -12.12

8 -^-v- -15.28

7 -^-v- -18.82

6 -^-v- -25.29

5 -^-v- -27.60

4 -^-v- -266.8

3 -^-v- -270.1

2 -^-v- -506.3

1 -^-v- -507.9

## 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 = -229.1787968090 Hartrees

*Note: The C-C bond is slightly rotated (15.6 degrees) from the lower energy rotamer, CH3COOH(7.6 degrees). This calculation may be useful in comparison with molecular mechanics torsional potential calculations.