## HOCN, Isocyanic acid

 H3 \ O1 - C2 E N4
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

O1 charge=-0.416
C2 charge= 0.500
H3 charge= 0.417
N4 charge=-0.500
with a dipole moment of 4.06002 Debye

## Bond Lengths:

between O1 and C2: distance=1.309 ang___ between O1 and H3: distance=0.980 ang___
between O1 and N4: distance=2.482 ang___ between C2 and N4: distance=1.174 ang___

## Bond Angles:

for H3-O1-C2: angle=110.8 deg___ for N4-C2-O1: angle=176.4 deg___

## Bond Orders (Mulliken):

between O1 and C2: order=0.894___ between O1 and H3: order=0.821___
between O1 and N4: order=0.066___ between C2 and N4: order=2.769___

## 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 O1-C2 with 1.9981 electrons
__has 65.03% O 1 character in a sp2.25 hybrid
__has 34.97% C 2 character in a sp1.28 hybrid

2. A bonding orbital for O1-H3 with 1.9736 electrons
__has 76.07% O 1 character in a s0.81 p3 hybrid
__has 23.93% H 3 character in a s orbital

3. A bonding orbital for C2-N4 with 1.9982 electrons
__has 44.13% C 2 character in a sp0.88 hybrid
__has 55.87% N 4 character in a sp1.59 hybrid

4. A bonding orbital for C2-N4 with 1.9968 electrons
__has 40.49% C 2 character in a p-pi orbital ( 99.70% p 0.30% d)
__has 59.51% N 4 character in a p-pi orbital ( 99.60% p 0.40% d)

5. A bonding orbital for C2-N4 with 1.9911 electrons
__has 44.60% C 2 character in a s0.09 p3 hybrid
__has 55.40% N 4 character in a s0.08 p3 hybrid

9. A lone pair orbital for O1 with 1.9589 electrons

10. A lone pair orbital for O1 with 1.9056 electrons
__made from a p-pi orbital ( 99.92% p 0.08% d)

11. A lone pair orbital for N4 with 1.9655 electrons

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

The interaction of bonding donor orbital, 2, for O1-H3 with the third antibonding acceptor orbital, 78, for C2-N4 is 58.5 kJ/mol.

The interaction of lone pair donor orbital, 9, for O1 with the antibonding acceptor orbital, 76, for C2-N4 is 67.4 kJ/mol.

The interaction of lone pair donor orbital, 9, for O1 with the third antibonding acceptor orbital, 78, for C2-N4 is 24.3 kJ/mol.

The interaction of the second lone pair donor orbital, 10, for O1 with the second antibonding acceptor orbital, 77, for C2-N4 is 209. kJ/mol.

The interaction of lone pair donor orbital, 11, for N4 with the antibonding acceptor orbital, 74, for O1-C2 is 97.2 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.

15 ----- 1.992

14 ----- 0.222

13 ----- -0.402

12 ----- -1.048

11 -^-v- -7.748

10 -^-v- -8.391

9 -^-v- -8.908

8 -^-v- -11.57

7 -^-v- -12.61

6 -^-v- -17.10

5 -^-v- -22.59

4 -^-v- -28.73

3 -^-v- -269.2

2 -^-v- -377.5

1 -^-v- -509.6

## 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 = -168.7052298550 Hartrees