I cannot agree that observing the relative change in Mulliken charges
instead of absolute values would be correct. I had experience that DZP
showed transfer of charge from surface to molecule, while TZP showed
the opposite (though the charge transfer itself was very smal - about
0.1e)
Was this an effect only in the Mulliken populations, or was it something
from the calculation? Did you checked was was really happening with the
charge transfer?
I believe, yes. The binding energies (if BSSE corrections are taken) and
the geometry were the same. I haven't checked too much, but I believe
that if I were to draw DRHO it would be pretty the same (at least
difference would not be noticeable by a naked eye).
While the Mulliken charges themselves were very different. And their
difference (i.e. charge transfer) was a little bit different.
