Based on previous studies, the first term 𝛼 M-Host ∆𝐺 °f,M 𝑛 represents the HSAB-like interaction as in eq. 2, while the second term 𝛽 M-Host /𝑟 M 𝑛 represents the size effect, distinct from eq. 2 and 3. Since this term involves the inverse of the ionic radius, it is considered to incorporate Coulombic energy.