  Partial charges are a central concept in general chemistry and chemical
biology, yet dozens of different computational definitions exist. In prior work
[M. Cho et al., \textit{ChemPhysChem} {\bf 21}, 688-696 (2020)], we showed that
these can be reduced to at most three `principal components of ionicity'. The
present study addressed the dependance on computed partial charges $q$ on
1-particle basis set and (for WFT methods) $n$-particle correlation treatment
or (for DFT methods) exchange-correlation functional, for several
representative partial charge definitions such as QTAIM, Hirshfeld,
Hirshfeld-I, HLY (electrostatic), NPA, and APT. Our findings show that
semi-empirical double hybrids can closely approach the CCSD(T) `gold standard'
for this property. In fact, owing to an error compensation in MP2, CCSD partial
charges are further away from CCSD(T) than is MP2. The non-local correlation is
important, especially when there is a substantial amount of non-local exchange.
Employing range separation provides no clear advantage, while global hybrids
with 20-30\% Hartree-Fock exchange exhibit the best performance across all
charge types. Basis set convergence analysis shows that an augmented
triple-zeta haVTZ+d basis set is sufficient for Hirshfeld, Hirshfeld-I, HLY,
and APT methods. In contrast, QTAIM and NPA display slower basis set
convergence. It is noteworthy that for both NPA and QTAIM, HF exhibits the
slowest basis set convergence when contrasted with the correlation components
of MP2 and CCSD. Triples corrections in CCSD(T), denoted as CCSD(T)-CCSD,
exhibit even faster basis set convergence.
