Extended Data Fig. 3: Comparison of the Li⁺ and Na⁺ solvation shell.

Coordination number between Li⁺ cation (blue) or Na⁺ cations (pink) and oxygen atoms from ClO₄⁻ anions (a), nitrogen atoms from acetonitrile molecules (b) and oxygen atoms from water molecules (c) in the presence of 100 mM of AClO₄ in acetonitrile containing 10% of water in mass. The simulation box for NaClO₄ was similar to the LiClO₄ one (Supplementary Table 1) and the Lennard-Jones parameters for Na⁺ were chosen from Åqvist⁵⁶. The number of water molecules and ClO₄^- anions present in the first solvation shell of the Na⁺ and Li⁺ cations is similar, while more acetonitrile is found in the case of Na⁺.