## HOSiH2O-

 H3 O5 \ / O1 - SI2 - H6 \ H4
The ion charge is -1.

## Atomic Charges and Dipole Moment

O1 charge=-0.843
SI2 charge= 1.014
H3 charge= 0.389
H4 charge=-0.277
O5 charge=-0.976
H6 charge=-0.307
with a dipole moment of 2.36737 Debye

## Bond Lengths:

between O1 and SI2: distance=1.745 ang___ between O1 and H3: distance=0.976 ang___
between SI2 and H4: distance=1.545 ang___ between SI2 and O5: distance=1.596 ang___
between SI2 and H6: distance=1.549 ang___

## Bond Angles:

for H3-O1-SI2: angle=105.5 deg___ for H4-SI2-O1: angle=99.50 deg___
for O5-SI2-O1: angle=113.6 deg___ for H6-SI2-O1: angle=102.8 deg___

## Bond Orders (Mulliken):

between O1 and SI2: order=0.669___ between O1 and H3: order=0.879___
between SI2 and H4: order=0.909___ between SI2 and O5: order=1.457___
between SI2 and H6: order=0.896___

## 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-Si2 with 1.9909 electrons
__has 86.25% O 1 character in a sp1.62 hybrid
__has 13.75% Si 2 character in a s0.83 p3 d0.08 hybrid

2. A bonding orbital for O1-H3 with 1.9917 electrons
__has 73.17% O 1 character in a s0.73 p3 hybrid
__has 26.83% H 3 character in a s orbital

3. A bonding orbital for Si2-H4 with 1.9754 electrons
__has 32.18% Si 2 character in a s0.96 p3 d0.07 hybrid
__has 67.82% H 4 character in a s orbital

4. A bonding orbital for Si2-O5 with 1.9935 electrons
__has 18.56% Si 2 character in a sp2.13 hybrid
__has 81.44% O 5 character in a sp1.33 hybrid

5. A bonding orbital for Si2-H6 with 1.9761 electrons
__has 31.86% Si 2 character in a s0.95 p3 d0.07 hybrid
__has 68.14% H 6 character in a s orbital

13. A lone pair orbital for O1 with 1.9853 electrons

14. A lone pair orbital for O1 with 1.9698 electrons

15. A lone pair orbital for O5 with 1.9856 electrons

16. A lone pair orbital for O5 with 1.8995 electrons
__made from a p-pi orbital ( 99.94% p 0.06% d)

17. A lone pair orbital for O5 with 1.8791 electrons

-With core pairs on: O 1 Si 2 Si 2 Si 2 Si 2 Si 2 O 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, 3, for Si2-H4 with the antibonding acceptor orbital, 93, for O1-Si2 is 24.0 kJ/mol.

The interaction of bonding donor orbital, 5, for Si2-H6 with the antibonding acceptor orbital, 93, for O1-Si2 is 24.9 kJ/mol.

The interaction of the second lone pair donor orbital, 14, for O1 with the antibonding acceptor orbital, 97, for Si2-H6 is 31.6 kJ/mol.

The interaction of the second lone pair donor orbital, 16, for O5 with the antibonding acceptor orbital, 95, for Si2-H4 is 54.3 kJ/mol.

The interaction of the second lone pair donor orbital, 16, for O5 with the antibonding acceptor orbital, 97, for Si2-H6 is 83.5 kJ/mol.

The interaction of the third lone pair donor orbital, 17, for O5 with the antibonding acceptor orbital, 93, for O1-Si2 is 112. kJ/mol.

The interaction of the third lone pair donor orbital, 17, for O5 with the antibonding acceptor orbital, 95, for Si2-H4 is 37.8 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.

21 ----- 7.448
20 ----- 7.020

19 ----- 5.640

18 ----- 5.050

17 -^-v- 0.129

16 -^-v- -0.205

15 -^-v- -1.447

14 -^-v- -1.707

13 -^-v- -3.331

12 -^-v- -3.579

11 -^-v- -5.000

10 -^-v- -7.595

9 -^-v- -15.45

8 -^-v- -18.96

7 -^-v- -88.45

6 -^-v- -88.56
5 -^-v- -88.61

4 -^-v- -130.9

3 -^-v- -498.4

2 -^-v- -500.8

1 -^-v- -1766.

## 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 = -441.9493978020 Hartrees