HCC•, dehydroacetylene radical

C3 E C1 - H2
The multiplicity is 2.

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=-0.578
H2 charge= 0.384
C3 charge= 0.194
with a dipole moment of 0.80287 Debye

Bond Lengths:

between C1 and H2: distance=1.076 ang___ between C1 and C3: distance=1.217 ang___
between H2 and C3: distance=2.293 ang___

Bond Angles:

for C3-C1-H2: angle=179.2 deg___

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Bond Orders (Mulliken):

between C1 and H2: order=0.849___ between C1 and C3: order=2.515___
between H2 and C3: order=0.071___

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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-H2 with 0.9962 electrons
__has 58.48% C 1 character in a sp1.05 hybrid
__has 41.52% H 2 character in a s orbital

2. A bonding orbital for C1-C3 with 0.9999 electrons
__has 28.89% C 1 character in a p-pi orbital ( 99.65% p 0.35% d)
__has 71.11% C 3 character in a p-pi orbital ( 99.94% p 0.06% d)

3. A bonding orbital for C1-C3 with 0.9999 electrons
__has 28.89% C 1 character in a p-pi orbital ( 99.65% p 0.35% d)
__has 71.11% C 3 character in a p-pi orbital ( 99.94% p 0.06% d)

4. A bonding orbital for C1-C3 with 0.9972 electrons
__has 54.54% C 1 character in a sp0.95 hybrid
__has 45.46% C 3 character in a sp0.94 hybrid

7. A lone pair orbital for C3 with 0.9914 electrons
__made from a sp1.05 hybrid

-With core pairs on: C 1 C 3 -

Up Electrons

1. A bonding orbital for C1-H2 with 0.9939 electrons
__has 64.97% C 1 character in a sp1.03 hybrid
__has 35.03% H 2 character in a s orbital

2. A bonding orbital for C1-C3 with 0.9999 electrons
__has 74.20% C 1 character in a p-pi orbital ( 99.89% p 0.10% d)
__has 25.80% C 3 character in a p3 hybrid

3. A bonding orbital for C1-C3 with 0.9999 electrons
__has 74.20% C 1 character in a p-pi orbital ( 99.90% p 0.10% d)
__has 25.80% C 3 character in a p-pi orbital ( 99.44% p 0.56% d)

4. A bonding orbital for C1-C3 with 0.9989 electrons
__has 58.38% C 1 character in a sp0.96 hybrid
__has 41.62% C 3 character in a sp0.49 hybrid

-With core pairs on: C 1 C 3 -

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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-H2 with the lone pair acceptor orbital, 7, for C3 is 27.6 kJ/mol.

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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.

11 ----- 3.760

10 ----- 1.734


9 ----- -0.904 8 ----- -0.904


7 -^--- -7.863 6 -^-v- -7.863


5 -^-v- -9.601


4 -^-v- -13.64


3 -^-v- -19.04


2 -^-v- -267.1


1 -^-v- -268.5

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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 = -76.6292557105 Hartrees

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