Visualizing Difference in Charge Density

[vimal]

Dear Friends,

I am looking at the dissociation of precursor molecule on SiO2 surface.

I have two cases.
one where the precursor fragments
and the other where the precursor doesn't get fragmented.

I wanted to explain this chemistry by the difference in charge transferred
from surface to molecule in terms of a figure.
Could anyone explain how this could be done using the provided scripts.

any comments and suggestions will be appreciated.

Best regards,
Vimal