As the title asks, is it possible to calculate the electronegativity (EN) of specific atoms on extended surfaces (slabs), more specifically using computational methods? There are a few issues here I am running into:
To find the Mulliken EN $\chi$, we can use the relation
$$\chi = \frac{E_\mathrm{i} + E_\mathrm{ea}}{2}$$
where $E_\mathrm{i} = E(\ce{M+}) - E(\ce{M})$ and $E_\mathrm{ea} = E(\ce{M})-E(\ce{M-})$. However, these energies are for the entire system, usually a molecule, and not the individual atoms. I hope I am not misunderstanding the concept here.
Alternatively certain definitions use $\chi = -\mu$, or the work function. Again, this is usually calculated on a surface basis, not per atom of site.
Is there no accurate determination method which is specific to the atom? Or is it conceptually impossible?