Hirshfeld analysis is fully compatible with diffuse functions. So, do not worry.
I'm calculating condensed Fukui functions to explain the reactivity of my molecules.
The manual for Multiwfn suggests using atomic dipole moment corrected Hirshfeld charges for it. However I get strange results, on some atoms in which f+ is negative.
I'm using def2-TZVPD basis set, and I'm wondering if diffuse functions can make Hirshfeld charges meaningless as they do for Mulliken charges?
I'm sorry to cross post from another forum, but I highly hope that my question will be answered here.