## BF4+

 F3 \\ B1 = F2 / F5 - F4
The ion charge is 1.

## Atomic Charges and Dipole Moment

B1 charge= 0.834
F2 charge=-0.038
F3 charge=-0.088
F4 charge= 0.098
F5 charge= 0.194
with a dipole moment of 0.27784 Debye

## Bond Lengths:

between B1 and F2: distance=1.281 ang___ between B1 and F3: distance=1.271 ang___
between B1 and F4: distance=1.640 ang___ between B1 and F5: distance=2.624 ang___
between F2 and F3: distance=2.434 ang___ between F3 and F4: distance=2.435 ang___
between F4 and F5: distance=1.461 ang___

## Bond Angles:

for F3-B1-F2: angle=145.0 deg___ for F4-B1-F2: angle=102.0 deg___
for F5-B1-F2: angle=132.2 deg___

## Bond Orders (Mulliken):

between B1 and F2: order=1.391___ between B1 and F3: order=1.374___
between B1 and F4: order=0.528___ between B1 and F5: order=0.051___
between F2 and F3: order=-0.073___ between F3 and F4: order=-0.060___
between F4 and F5: order=0.853___

## 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 B1-F2 with 1.9939 electrons
__has 17.12% B 1 character in a sp1.52 hybrid
__has 82.88% F 2 character in a sp1.64 hybrid

2. A bonding orbital for B1-F3 with 1.9948 electrons
__has 16.96% B 1 character in a sp1.52 hybrid
__has 83.04% F 3 character in a sp1.55 hybrid

3. A bonding orbital for B1-F3 with 1.9996 electrons
__has 5.82% B 1 character in a p-pi orbital ( 96.89% p 3.11% d)
__has 94.18% F 3 character in a p-pi orbital ( 99.91% p 0.09% d)

4. A bonding orbital for B1-F4 with 1.9873 electrons
__has 9.09% B 1 character in a s0.81 p3 hybrid
__has 90.91% F 4 character in a sp2.39 hybrid

5. A bonding orbital for F4-F5 with 1.9958 electrons
__has 64.31% F 4 character in a s0.32 p3 hybrid
__has 35.69% F 5 character in a s0.08 p3 hybrid

11. A lone pair orbital for F2 with 1.9838 electrons

12. A lone pair orbital for F2 with 1.9260 electrons

13. A lone pair orbital for F2 with 1.8899 electrons

14. A lone pair orbital for F3 with 1.9840 electrons

15. A lone pair orbital for F3 with 1.9244 electrons

16. A lone pair orbital for F4 with 1.9947 electrons

17. A lone pair orbital for F4 with 1.9843 electrons

18. A lone pair orbital for F5 with 1.9997 electrons

19. A lone pair orbital for F5 with 1.9996 electrons

20. A lone pair orbital for F5 with 1.9986 electrons
__made from a s0.49 p3 hybrid

118. A antibonding orbital for B1-F3 with 0.1098 electrons
__has 94.18% B 1 character in a p-pi orbital ( 96.89% p 3.11% d)
__has 5.82% F 3 character in a p-pi orbital ( 99.91% p 0.09% d)

119. A antibonding orbital for B1-F4 with 0.1113 electrons
__has 90.91% B 1 character in a s0.81 p3 hybrid
__has 9.09% F 4 character in a sp2.39 hybrid

-With core pairs on: B 1 F 2 F 3 F 4 F 5 -

#### 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, 4, for B1-F4 with the antibonding acceptor orbital, 120, for F4-F5 is 22.3 kJ/mol.

The interaction of the second lone pair donor orbital, 12, for F2 with the antibonding acceptor orbital, 117, for B1-F3 is 41.0 kJ/mol.

The interaction of the second lone pair donor orbital, 12, for F2 with the antibonding acceptor orbital, 119, for B1-F4 is 123. kJ/mol.

The interaction of the third lone pair donor orbital, 13, for F2 with the second antibonding acceptor orbital, 118, for B1-F3 is 213. kJ/mol.

The interaction of the second lone pair donor orbital, 15, for F3 with the antibonding acceptor orbital, 116, for B1-F2 is 41.4 kJ/mol.

The interaction of the second lone pair donor orbital, 15, for F3 with the antibonding acceptor orbital, 119, for B1-F4 is 137. kJ/mol.

The interaction of the second lone pair donor orbital, 17, for F4 with the second antibonding acceptor orbital, 118, for B1-F3 is 32.9 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.

24 ----- -5.408

23 ----- -8.215

22 ----- -9.041

21 ----- -15.49

20 -^-v- -17.97

19 -^-v- -18.22

18 -^-v- -18.95

17 -^-v- -19.13

16 -^-v- -19.68

15 -^-v- -20.37

14 -^-v- -21.84
13 -^-v- -21.86

12 -^-v- -22.16

11 -^-v- -23.07

10 -^-v- -25.00

9 -^-v- -36.45

8 -^-v- -39.36

7 -^-v- -39.48

6 -^-v- -42.38

5 -^-v- -188.3

4 -^-v- -665.1

3 -^-v- -665.3

2 -^-v- -666.8

1 -^-v- -668.5

## 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 = -423.9569427091 Hartrees