## Si4 tetrahedral*

 Si3 / | Si4 - Si2
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=-0.004
SI2 charge=-0.005
SI3 charge= 0.004
SI4 charge= 0.005
with a dipole moment of 0.00506 Debye

## Bond Lengths:

between SI1 and SI2: distance=2.525 ang___ between SI1 and SI3: distance=2.526 ang___
between SI1 and SI4: distance=2.525 ang___ between SI2 and SI3: distance=2.526 ang___
between SI2 and SI4: distance=2.526 ang___ between SI3 and SI4: distance=2.526 ang___

## Bond Angles:

for SI3-SI1-SI2: angle=60.00 deg___ for SI4-SI1-SI2: angle=60.01 deg___

## Bond Orders (Mulliken):

between SI1 and SI2: order=1.419___ between SI1 and SI3: order=0.574___
between SI1 and SI4: order=1.242___ between SI2 and SI3: order=1.078___
between SI2 and SI4: order=0.597___ between SI3 and SI4: order=0.355___

## 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 Si1-Si2 with 1.9376 electrons
__has 46.93% Si 1 character in a s0.32 p3 hybrid
__has 53.07% Si 2 character in a s0.22 p3 hybrid

2. A bonding orbital for Si1-Si4 with 1.7031 electrons
__has 55.30% Si 1 character in a s0.38 p3 hybrid
__has 44.70% Si 4 character in a s0.09 p3 hybrid

3. A bonding orbital for Si2-Si3 with 1.7499 electrons
__has 56.59% Si 2 character in a s0.31 p3 hybrid
__has 43.41% Si 3 character in a s0.21 p3 d0.05 hybrid

4. A bonding orbital for Si2-Si4 with 1.4799 electrons
__has 55.36% Si 2 character in a s0.33 p3 d0.05 hybrid
__has 44.64% Si 4 character in a s0.16 p3 d0.05 hybrid

25. A lone pair orbital for Si1 with 1.9680 electrons

26. A lone pair orbital for Si1 with 0.4570 electrons
__made from a p3 d0.08 hybrid

27. A lone pair orbital for Si2 with 1.9436 electrons

28. A lone pair orbital for Si3 with 1.9384 electrons

29. A lone pair orbital for Si3 with 0.4921 electrons
__made from a s0.11 p3 d0.05 hybrid

30. A lone pair orbital for Si3 with 0.1510 electrons
__made from a s0.52 p3 d0.15 hybrid

31. A lone pair orbital for Si4 with 1.9103 electrons

32. A lone pair orbital for Si4 with 0.1082 electrons
__made from a s0.17 p3 d0.05 hybrid

-With core pairs on:Si 1 Si 1 Si 1 Si 1 Si 1 Si 2 Si 2 Si 2 Si 2 Si 2 Si 3 Si 3 Si 3 Si 3 Si 3 Si 4 Si 4 Si 4 Si 4 Si 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, 1, for Si1-Si2 with the bonding acceptor orbital, 4, for Si2-Si4 is 107. kJ/mol.

The interaction of bonding donor orbital, 1, for Si1-Si2 with the second lone pair acceptor orbital, 29, for Si3 is 149. kJ/mol.

The interaction of bonding donor orbital, 1, for Si1-Si2 with the third lone pair acceptor orbital, 30, for Si3 is 72.2 kJ/mol.

The interaction of bonding donor orbital, 1, for Si1-Si2 with the second lone pair acceptor orbital, 32, for Si4 is 111. kJ/mol.

The interaction of bonding donor orbital, 1, for Si1-Si2 with the antibonding acceptor orbital, 121, for Si1-Si2 is 177. kJ/mol.

The interaction of bonding donor orbital, 1, for Si1-Si2 with the antibonding acceptor orbital, 122, for Si1-Si4 is 60.4 kJ/mol.

The interaction of bonding donor orbital, 2, for Si1-Si4 with the bonding acceptor orbital, 4, for Si2-Si4 is 141. kJ/mol.

The interaction of bonding donor orbital, 2, for Si1-Si4 with the second lone pair acceptor orbital, 29, for Si3 is 394. kJ/mol.

The interaction of bonding donor orbital, 2, for Si1-Si4 with the third lone pair acceptor orbital, 30, for Si3 is 104. kJ/mol.

The interaction of bonding donor orbital, 2, for Si1-Si4 with the second lone pair acceptor orbital, 32, for Si4 is 317. kJ/mol.

The interaction of bonding donor orbital, 2, for Si1-Si4 with the antibonding acceptor orbital, 122, for Si1-Si4 is 221. kJ/mol.

The interaction of bonding donor orbital, 3, for Si2-Si3 with the bonding acceptor orbital, 4, for Si2-Si4 is 1126 kJ/mol.

The interaction of bonding donor orbital, 3, for Si2-Si3 with the third lone pair acceptor orbital, 30, for Si3 is 298. kJ/mol.

The interaction of bonding donor orbital, 3, for Si2-Si3 with the antibonding acceptor orbital, 122, for Si1-Si4 is 32.7 kJ/mol.

The interaction of bonding donor orbital, 3, for Si2-Si3 with the antibonding acceptor orbital, 123, for Si2-Si3 is 25.5 kJ/mol.

The interaction of bonding donor orbital, 3, for Si2-Si3 with the antibonding acceptor orbital, 124, for Si2-Si4 is 24.9 kJ/mol.

The interaction of bonding donor orbital, 4, for Si2-Si4 with the third lone pair acceptor orbital, 30, for Si3 is 99.2 kJ/mol.

The interaction of bonding donor orbital, 4, for Si2-Si4 with the second lone pair acceptor orbital, 32, for Si4 is 134. kJ/mol.

The interaction of bonding donor orbital, 4, for Si2-Si4 with the antibonding acceptor orbital, 122, for Si1-Si4 is 23.5 kJ/mol.

The interaction of bonding donor orbital, 4, for Si2-Si4 with the antibonding acceptor orbital, 123, for Si2-Si3 is 25.6 kJ/mol.

The interaction of bonding donor orbital, 4, for Si2-Si4 with the antibonding acceptor orbital, 124, for Si2-Si4 is 29.4 kJ/mol.

The interaction of lone pair donor orbital, 25, for Si1 with the second lone pair acceptor orbital, 29, for Si3 is 90.4 kJ/mol.

The interaction of the second lone pair donor orbital, 26, for Si1 with the bonding acceptor orbital, 4, for Si2-Si4 is 96.2 kJ/mol.

The interaction of the second lone pair donor orbital, 26, for Si1 with the second lone pair acceptor orbital, 29, for Si3 is 345. kJ/mol.

The interaction of lone pair donor orbital, 27, for Si2 with the second lone pair acceptor orbital, 32, for Si4 is 25.4 kJ/mol.

The interaction of lone pair donor orbital, 28, for Si3 with the second lone pair acceptor orbital, 26, for Si1 is 191. kJ/mol.

The interaction of lone pair donor orbital, 28, for Si3 with the second lone pair acceptor orbital, 29, for Si3 is 191. kJ/mol.

The interaction of lone pair donor orbital, 28, for Si3 with the third lone pair acceptor orbital, 30, for Si3 is 35.8 kJ/mol.

The interaction of lone pair donor orbital, 28, for Si3 with the second lone pair acceptor orbital, 32, for Si4 is 132. kJ/mol.

The interaction of the second lone pair donor orbital, 29, for Si3 with the third lone pair acceptor orbital, 30, for Si3 is 116. kJ/mol.

The interaction of the second lone pair donor orbital, 29, for Si3 with the second lone pair acceptor orbital, 32, for Si4 is 91.4 kJ/mol.

The interaction of the third lone pair donor orbital, 30, for Si3 with the second lone pair acceptor orbital, 32, for Si4 is 793. kJ/mol.

The interaction of lone pair donor orbital, 31, for Si4 with the bonding acceptor orbital, 4, for Si2-Si4 is 131. kJ/mol.

The interaction of lone pair donor orbital, 31, for Si4 with the second lone pair acceptor orbital, 26, for Si1 is 43.8 kJ/mol.

The interaction of lone pair donor orbital, 31, for Si4 with the third lone pair acceptor orbital, 30, for Si3 is 263. kJ/mol.

The interaction of lone pair donor orbital, 31, for Si4 with the second lone pair acceptor orbital, 32, for Si4 is 125. 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.

32 ----- -1.320 31 ----- -1.322

30 ----- -5.248 29 ----- -5.250

28 -^-v- -5.682 27 -^-v- -5.682 26 -^-v- -5.685

25 -^-v- -6.405

24 -^-v- -10.59 23 -^-v- -10.60 22 -^-v- -10.60

21 -^-v- -15.61

20 -^-v- -95.10 19 -^-v- -95.10 18 -^-v- -95.10
17 -^-v- -95.11
16 -^-v- -95.19 15 -^-v- -95.20 14 -^-v- -95.20 13 -^-v- -95.20 12 -^-v- -95.20 11 -^-v- -95.20 10 -^-v- -95.21 9 -^-v- -95.21

8 -^-v- -137.5 7 -^-v- -137.5 6 -^-v- -137.5 5 -^-v- -137.5

4 -^-v- -1773. 3 -^-v- -1773. 2 -^-v- -1773. 1 -^-v- -1773.

## 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 = -1157.9149459467 Hartrees

* Also check the planar conformer