O3...Br- complex

 BR3 O1 = O2 // O4
The ion charge is -1.

Atomic Charges and Dipole Moment

O1 charge= 0.206
O2 charge=-0.267
BR3 charge=-0.672
O4 charge=-0.266
with a dipole moment of 8.36046 Debye

Bond Lengths:

between O1 and O2: distance=1.325 ang___ between O1 and BR3: distance=3.337 ang___
between O1 and O4: distance=1.321 ang___ between O2 and O4: distance=2.237 ang___

Bond Angles:

for BR3-O1-O2: angle=110.5 deg___ for O4-O1-O2: angle=115.4 deg___

Bond Orders (Mulliken):

between O1 and O2: order=1.383___ between O1 and BR3: order=0.121___
between O1 and O4: order=1.398___ between O2 and O4: order=0.367___

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 O1-O2 with 1.9953 electrons
__has 60.98% O 1 character in a s0.86 p3 hybrid
__has 39.02% O 2 character in a s0.38 p3 hybrid

2. A bonding orbital for O1-O4 with 1.9985 electrons
__has 41.62% O 1 character in a p3 hybrid
__has 58.38% O 4 character in a p3 hybrid

3. A bonding orbital for O1-O4 with 1.9953 electrons
__has 60.65% O 1 character in a s0.86 p3 hybrid
__has 39.35% O 4 character in a s0.39 p3 hybrid

21. A lone pair orbital for O1 with 1.9973 electrons

22. A lone pair orbital for O2 with 1.9988 electrons

23. A lone pair orbital for O2 with 1.9713 electrons
__made from a s0.29 p3 hybrid

24. A lone pair orbital for O2 with 1.4241 electrons

25. A lone pair orbital for Br3 with 1.9999 electrons

26. A lone pair orbital for Br3 with 1.9999 electrons
__made from a s0.10 p3 hybrid

27. A lone pair orbital for Br3 with 1.9999 electrons
__made from a s0.38 p3 hybrid

28. A lone pair orbital for Br3 with 1.9768 electrons

29. A lone pair orbital for O4 with 1.9988 electrons

30. A lone pair orbital for O4 with 1.9710 electrons
__made from a s0.29 p3 hybrid

90. A antibonding orbital for O1-O4 with 0.5893 electrons
__has 58.38% O 1 character in a p3 hybrid
__has 41.62% O 4 character in a p3 hybrid

-With core pairs on: O 1 O 2 Br 3 Br 3 Br 3 Br 3 Br 3 Br 3 Br 3 Br 3 Br 3 Br 3 Br 3 Br 3 Br 3 Br 3 O 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 O1-O4 with the third lone pair acceptor orbital, 24, for O2 is 56.9 kJ/mol.

The interaction of bonding donor orbital, 2, for O1-O4 with the antibonding acceptor orbital, 90, for O1-O4 is 30.2 kJ/mol.

The interaction of the second lone pair donor orbital, 23, for O2 with the second antibonding acceptor orbital, 91, for O1-O4 is 57.9 kJ/mol.

The interaction of the third lone pair donor orbital, 24, for O2 with the antibonding acceptor orbital, 90, for O1-O4 is 1199 kJ/mol.

The interaction of the second lone pair donor orbital, 30, for O4 with the antibonding acceptor orbital, 89, for O1-O2 is 58.6 kJ/mol.

The interaction of 4th lone pair donor orbital, 28, for Br3 with the antibonding acceptor orbital, 90, for O1-O4 is 18.5 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.

34 ----- 10.62

33 ----- 6.030

32 ----- 4.205

31 ----- -1.070
30 -^-v- -1.098
29 -^-v- -1.110

28 -^-v- -1.363

27 -^-v- -2.733
26 -^-v- -2.802

25 -^-v- -3.715

24 -^-v- -8.640

23 -^-v- -8.906

22 -^-v- -9.230

21 -^-v- -12.40

20 -^-v- -14.00

19 -^-v- -21.16

18 -^-v- -27.66

17 -^-v- -61.86 16 -^-v- -61.86

15 -^-v- -61.99 14 -^-v- -61.99
13 -^-v- -62.03

12 -^-v- -165.1 11 -^-v- -165.1

10 -^-v- -165.2

9 -^-v- -222.4

8 -^-v- -503.9
7 -^-v- -503.9

6 -^-v- -508.4

5 -^-v- -1511. 4 -^-v- -1511.
3 -^-v- -1511.

2 -^-v- -1674.

1 -^-v- -13060

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 = -2799.6339553782 Hartrees