The distribution of NO - 3 and Cl -ions for varying numbers of DCPAM molecules (N DCPAM ) and c s (cf. Figs. and). NO - 3 ions are predominantly localized at a distance of about 0.46 nm from the N + sites of the -N + (CH 3 ) 3 groups, accompanied by minor peaks in the longer-range regions. Cl -ions exhibit a similar trend, but their main peak is shorter and broader, reflecting weaker and less localized interactions. Furthermore, as c s increases, the density of Cl -ions close to the N + atoms of B-block decreases, indicating competitive interactions between NO - 3 and Cl -ions. Quantum mechanical calculations summarized in Sect. SIII reveal that the ionic bonds in NaCl are stronger than those in NaNO 3 (see Fig. ). This finding supports the hypothesis that NaNO 3 dissociates in solution, allowing the Na + and Cl -ions to attract each other, while the NO - 3 ions remain more freely mobile. These observations are consistent with the lower solubility of NaCl as compared to NaNO 3 , as previously reported in Ref. . Subsequently, the NO - 3 ions can be attracted to the DCPAMs. Additionally, our findings are consistent with the Hofmeister series, which predicts that NO - 3 associates with positively charged nitrogen in -N + (CH 3 ) 3 , while Cl -favors Na + ions .