## NCO-, Cyanate ion

 N3 E C1 - O2
The ion charge is -1.

## Atomic Charges and Dipole Moment

C1 charge= 0.627
O2 charge=-0.694
N3 charge=-0.932
with a dipole moment of 1.62207 Debye

## Bond Lengths:

between C1 and O2: distance=1.243 ang___ between C1 and N3: distance=1.207 ang___
between O2 and N3: distance=2.449 ang___

## Bond Angles:

for N3-C1-O2: angle=179.9 deg___

## Bond Orders (Mulliken):

between C1 and O2: order=1.283___ between C1 and N3: order=2.502___
between O2 and N3: order=0.123___

## 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-O2 with 1.9984 electrons
__has 36.86% C 1 character in a sp1.18 hybrid
__has 63.14% O 2 character in a sp1.86 hybrid

2. A bonding orbital for C1-N3 with 1.9980 electrons
__has 43.70% C 1 character in a sp0.85 hybrid
__has 56.30% N 3 character in a sp1.45 hybrid

3. A bonding orbital for C1-N3 with 1.9954 electrons
__has 34.00% C 1 character in a p-pi orbital ( 99.62% p 0.38% d)
__has 66.00% N 3 character in a p-pi orbital ( 99.71% p 0.29% d)

4. A bonding orbital for C1-N3 with 1.9954 electrons
__has 34.00% C 1 character in a p-pi orbital ( 99.62% p 0.38% d)
__has 66.00% N 3 character in a p-pi orbital ( 99.71% p 0.29% d)

8. A lone pair orbital for O2 with 1.9698 electrons
__made from a sp0.53 hybrid

9. A lone pair orbital for O2 with 1.7981 electrons
__made from a p-pi orbital ( 99.89% p 0.11% d)

10. A lone pair orbital for O2 with 1.7981 electrons
__made from a p-pi orbital ( 99.89% p 0.11% d)

11. A lone pair orbital for N3 with 1.9633 electrons
__made from a sp0.68 hybrid

71. A antibonding orbital for C1-N3 with 0.1930 electrons
__has 66.00% C 1 character in a p-pi orbital ( 99.62% p 0.38% d)
__has 34.00% N 3 character in a p-pi orbital ( 99.71% p 0.29% d)

72. A antibonding orbital for C1-N3 with 0.1930 electrons
__has 66.00% C 1 character in a p-pi orbital ( 99.62% p 0.38% d)
__has 34.00% N 3 character in a p-pi orbital ( 99.71% p 0.29% d)

-With core pairs on: C 1 O 2 N 3 -

#### 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, 1, for C1-O2 with the antibonding acceptor orbital, 70, for C1-N3 is 22.5 kJ/mol.

The interaction of lone pair donor orbital, 8, for O2 with the antibonding acceptor orbital, 70, for C1-N3 is 100. kJ/mol.

The interaction of the second lone pair donor orbital, 9, for O2 with the third antibonding acceptor orbital, 72, for C1-N3 is 433. kJ/mol.

The interaction of the third lone pair donor orbital, 10, for O2 with the second antibonding acceptor orbital, 71, for C1-N3 is 433. kJ/mol.

The interaction of lone pair donor orbital, 11, for N3 with the antibonding acceptor orbital, 69, for C1-O2 is 99.2 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 ----- 9.708

14 ----- 8.145
13 ----- 7.574 12 ----- 7.573

11 -^-v- 0.239 10 -^-v- 0.239

9 -^-v- -2.009

8 -^-v- -3.622 7 -^-v- -3.623

6 -^-v- -5.360

5 -^-v- -14.83

4 -^-v- -19.38

3 -^-v- -261.7

2 -^-v- -369.8

1 -^-v- -500.2

## 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 = -168.1972950784 Hartrees

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