## Cyclic HNCO, Cyclic cyanic acid

 O3 - C4 \ | N1 - H2
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

N1 charge=-0.270
H2 charge= 0.349
O3 charge= 0.016
C4 charge=-0.094
with a dipole moment of 1.95534 Debye

## Bond Lengths:

between N1 and H2: distance=1.041 ang___ between N1 and O3: distance=1.579 ang___
between N1 and C4: distance=1.461 ang___ between O3 and C4: distance=1.299 ang___

## Bond Angles:

for O3-N1-H2: angle=103.1 deg___ for C4-N1-H2: angle=106.6 deg___

## Bond Orders (Mulliken):

between N1 and H2: order=0.883___ between N1 and O3: order=0.806___
between N1 and C4: order=0.935___ between O3 and C4: order=1.087___

## 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.

### Hybridization in the Best Lewis Structure

1. A bonding orbital for N1-H2 with 1.9799 electrons
__has 67.58% N 1 character in a s0.86 p3 hybrid
__has 32.42% H 2 character in a s orbital

2. A bonding orbital for N1-O3 with 1.9785 electrons
__has 37.66% N 1 character in a s0.10 p3 hybrid
__has 62.34% O 3 character in a s0.16 p3 hybrid

3. A bonding orbital for N1-C4 with 1.9632 electrons
__has 66.95% N 1 character in a s0.86 p3 hybrid
__has 33.05% C 4 character in a s0.52 p3 hybrid

4. A bonding orbital for O3-C4 with 1.9839 electrons
__has 72.18% O 3 character in a sp2.51 hybrid
__has 27.82% C 4 character in a s0.66 p3 hybrid

5. A bonding orbital for O3-C4 with 1.9903 electrons
__has 88.81% O 3 character in a p3 hybrid
__has 11.19% C 4 character in a p3 d0.05 hybrid

9. A lone pair orbital for N1 with 1.9680 electrons

10. A lone pair orbital for O3 with 1.9927 electrons

11. A lone pair orbital for C4 with 1.9936 electrons

-With core pairs on: N 1 O 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.

The interaction of bonding donor orbital, 2, for N1-O3 with the antibonding acceptor orbital, 76, for N1-C4 is 41.0 kJ/mol.

The interaction of bonding donor orbital, 2, for N1-O3 with the antibonding acceptor orbital, 77, for O3-C4 is 34.1 kJ/mol.

The interaction of bonding donor orbital, 3, for N1-C4 with the antibonding acceptor orbital, 75, for N1-O3 is 60.4 kJ/mol.

The interaction of bonding donor orbital, 4, for O3-C4 with the antibonding acceptor orbital, 75, for N1-O3 is 22.5 kJ/mol.

The interaction of lone pair donor orbital, 9, for N1 with the second antibonding acceptor orbital, 78, for O3-C4 is 39.8 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 ----- 1.640

14 ----- 0.747

13 ----- -3.209

12 ----- -3.333

11 -^-v- -7.057

10 -^-v- -7.954

9 -^-v- -10.56

8 -^-v- -11.91

7 -^-v- -13.54

6 -^-v- -15.47

5 -^-v- -20.98

4 -^-v- -29.93

3 -^-v- -269.8

2 -^-v- -380.0

1 -^-v- -509.9

## 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 = -168.5795911277 Hartrees