## SiClBr

 SI3 / \ CL1 BR2
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

CL1 charge=-0.129
BR2 charge=-0.141
SI3 charge= 0.270
with a dipole moment of 1.28773 Debye

## Bond Lengths:

between CL1 and SI3: distance=2.125 ang___ between BR2 and SI3: distance=2.307 ang___

## Bond Angles:

for SI3-CL1-BR2: angle=40.25 deg___

## Bond Orders (Mulliken):

between CL1 and SI3: order=0.844___ between BR2 and SI3: order=0.780___

## 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 Cl1-Si3 with 1.9943 electrons
__has 81.20% Cl 1 character in a s0.80 p3 hybrid
__has 18.80% Si 3 character in a s0.31 p3 d0.11 hybrid

2. A bonding orbital for Br2-Si3 with 1.9928 electrons
__has 78.28% Br 2 character in a s0.60 p3 hybrid
__has 21.72% Si 3 character in a s0.27 p3 d0.09 hybrid

27. A lone pair orbital for Cl1 with 1.9950 electrons

28. A lone pair orbital for Cl1 with 1.9668 electrons
__made from a s0.07 p3 hybrid

29. A lone pair orbital for Cl1 with 1.9141 electrons
__made from a p-pi orbital ( 99.91% p 0.09% d)

30. A lone pair orbital for Br2 with 1.9966 electrons

31. A lone pair orbital for Br2 with 1.9680 electrons
__made from a s0.05 p3 hybrid

32. A lone pair orbital for Br2 with 1.9103 electrons
__made from a p-pi orbital ( 99.79% p 0.21% d)

33. A lone pair orbital for Si3 with 1.9980 electrons

34. A lone pair orbital for Si3 with 0.1706 electrons
__made from a p-pi orbital ( 98.11% p 1.89% d)

-With core pairs on:Cl 1 Cl 1 Cl 1 Cl 1 Cl 1 Br 2 Br 2 Br 2 Br 2 Br 2 Br 2 Br 2 Br 2 Br 2 Br 2 Br 2 Br 2 Br 2 Br 2 Si 3 Si 3 Si 3 Si 3 Si 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 the second lone pair donor orbital, 28, for Cl1 with the antibonding acceptor orbital, 90, for Br2-Si3 is 34.4 kJ/mol.

The interaction of the third lone pair donor orbital, 29, for Cl1 with the second lone pair acceptor orbital, 34, for Si3 is 119. kJ/mol.

The interaction of the second lone pair donor orbital, 31, for Br2 with the antibonding acceptor orbital, 89, for Cl1-Si3 is 29.7 kJ/mol.

The interaction of the third lone pair donor orbital, 32, for Br2 with the second lone pair acceptor orbital, 34, for Si3 is 113. 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.

37 ----- 2.667

36 ----- -1.307

35 ----- -1.629

34 ----- -4.151

33 -^-v- -6.882

32 -^-v- -7.595

31 -^-v- -7.951

30 -^-v- -8.910
29 -^-v- -8.965

28 -^-v- -10.00

27 -^-v- -12.83

26 -^-v- -19.74

25 -^-v- -20.97

24 -^-v- -68.64 23 -^-v- -68.65

22 -^-v- -68.75
21 -^-v- -68.82
20 -^-v- -68.85

19 -^-v- -96.52
18 -^-v- -96.60

17 -^-v- -96.74

16 -^-v- -138.9

15 -^-v- -171.8
14 -^-v- -171.9

13 -^-v- -172.0

12 -^-v- -190.6
11 -^-v- -190.7
10 -^-v- -190.7

9 -^-v- -229.2

8 -^-v- -249.0

7 -^-v- -1517.
6 -^-v- -1517.
5 -^-v- -1517.

4 -^-v- -1680.

3 -^-v- -1774.

2 -^-v- -2730.

1 -^-v- -13067

## 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 = -3323.8168097554 Hartrees