## SiF2

 F3 - SI1 - F2
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

SI1 charge= 0.891
F2 charge=-0.445
F3 charge=-0.445
with a dipole moment of 0.00151 Debye

## Bond Lengths:

between SI1 and F2: distance=1.666 ang___ between SI1 and F3: distance=1.666 ang___
between F2 and F3: distance=3.331 ang___

## Bond Angles:

for F3-SI1-F2: angle=179.8 deg___

## Bond Orders (Mulliken):

between SI1 and F2: order=0.789___ between SI1 and F3: order=0.692___
between F2 and F3: order=-0.104___

## 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 Si1-F2 with 1.9656 electrons
__has 4.94% Si 1 character in a p2.04 d2 hybrid
__has 95.06% F 2 character in a p-pi orbital ( 99.98% p)

2. A bonding orbital for Si1-F2 with 1.9656 electrons
__has 4.95% Si 1 character in a p2.04 d2 hybrid
__has 95.05% F 2 character in a p-pi orbital ( 99.98% p)

3. A bonding orbital for Si1-F2 with 1.9860 electrons
__has 7.55% Si 1 character in a sp1.50 d0.52 hybrid
__has 92.45% F 2 character in a sp2.73 hybrid

4. A bonding orbital for Si1-F3 with 1.9694 electrons
__has 4.40% Si 1 character in a p1.95 d2 hybrid
__has 95.60% F 3 character in a p-pi orbital ( 99.97% p)

5. A bonding orbital for Si1-F3 with 1.9694 electrons
__has 4.40% Si 1 character in a p1.95 d2 hybrid
__has 95.60% F 3 character in a p-pi orbital ( 99.97% p)

6. A bonding orbital for Si1-F3 with 1.9866 electrons
__has 7.27% Si 1 character in a sp1.58 d0.55 hybrid
__has 92.73% F 3 character in a sp2.59 hybrid

14. A lone pair orbital for Si1 with 1.9707 electrons

15. A lone pair orbital for F2 with 1.9901 electrons

16. A lone pair orbital for F3 with 1.9905 electrons

-With core pairs on:Si 1 Si 1 Si 1 Si 1 Si 1 F 2 F 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 Si1-F2 with the antibonding acceptor orbital, 77, for Si1-F3 is 73.3 kJ/mol.

The interaction of the second bonding donor orbital, 2, for Si1-F2 with the second antibonding acceptor orbital, 78, for Si1-F3 is 73.4 kJ/mol.

The interaction of the third bonding donor orbital, 3, for Si1-F2 with the third antibonding acceptor orbital, 79, for Si1-F3 is 78.4 kJ/mol.

The interaction of bonding donor orbital, 4, for Si1-F3 with the antibonding acceptor orbital, 74, for Si1-F2 is 66.9 kJ/mol.

The interaction of the second bonding donor orbital, 5, for Si1-F3 with the second antibonding acceptor orbital, 75, for Si1-F2 is 66.9 kJ/mol.

The interaction of the third bonding donor orbital, 6, for Si1-F3 with the third antibonding acceptor orbital, 76, for Si1-F2 is 77.0 kJ/mol.

The interaction of lone pair donor orbital, 15, for F2 with the third antibonding acceptor orbital, 79, for Si1-F3 is 39.7 kJ/mol.

The interaction of lone pair donor orbital, 16, for F3 with the third antibonding acceptor orbital, 76, for Si1-F2 is 38.7 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 ----- 3.375

19 ----- 1.370

18 ----- -3.495 17 ----- -3.498

16 -^-v- -6.531

15 -^-v- -10.56 14 -^-v- -10.56

13 -^-v- -10.90 12 -^-v- -10.90

11 -^-v- -12.22

10 -^-v- -13.76

9 -^-v- -29.24

8 -^-v- -29.40

7 -^-v- -96.87
6 -^-v- -96.95 5 -^-v- -96.96

4 -^-v- -139.2

3 -^-v- -655.8 2 -^-v- -655.8

1 -^-v- -1775.

## 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 = -489.3237967044 Hartrees