Of course molecular shape and the VSEPR model come up frequently.
As discussed previously in a valence bond picture like VSEPR, the lone pair electrons are closer to the atom than bonding pairs, and "fatter."
I can think of a few ways of quantifying this, but I'm trying to add more data when discussing molecular shape:
- Are there examples where the lone pair distance is estimated (e.g., for ozone or $\ce{NO2}$)? This could be compared to a typical bond length.
- Is there an example where the lone pair volume is quantified (e.g., through a polarizability volume, or an electron density isosurface)?
VSEPR is typically used to give qualitative valence bond understanding of shapes, but the lone pair effects are often confusing. So I'm wondering if data on volume / position can help clarify these effects for students.