Sulfur dioxide (SO2)
The geometry optimizatin at each level of theory shows the bond lengths and angle. At each level of theory the geometry is slightly different.
The expected values of the bond length is 1.4308 Angstroms and the bond angle is 119.329 degrees.
The geometry optimization of Sulfur dioxide at 6-31G level of theory is shown below.

At 6-21G level of theory, the geometry optimization of Sulfur dioxide is shown below.


The geometry optimization of Sulfur dioxide at double zeta valence (DZV) is shown by clicking the button below.


Using the double zeta valence, a displayed of the highest occupied molecular orbitals (HOMO) is shown below.


A displayed of the lowest unoccpied molecular orbitals (LUMO) was produced using the double zeta valence.



Using double zeta valence, the molecular electrostatic potential was produced.


The partial atomic charges of Sulfur dioxide was produced at the double zeta valence level of theory.

The partial atomic charges provides the same information as the electrostatic potential.

Table 1:Dipole Moment from DZV

Dipole Moment	Dipole Moment (D)
DZV	1.761969
Experimental	1.633*10^-6

Table 1 shows the dipole moment of the DZV vs the experimental value.

The link below shows the vibrational spectrum was found for SO2.   http://webbook.nist.gov/cgi/cbook.cgi?ID=C7446095&Units=SI&Type=IR-SPEC&Index=0#IR-SPEC




There were three modes of motions.
The button below will display SO2 at the highest vibrations calculated was at 1165.23 cm^-1.


The display below of SO2 is at 1060.21 cm^-1 vibrations. 


The vibrations of SO2 at 479.9 cm^-1 is shown below.
These three experimental vibrations are different from the spectrum because the calculations were incorrect with the electrons pairs.