In the regions of decreasing or increasing E bind values, the graphs are quite close to linear or exponential dependencies. In case of s/s (schematic notation: solvent molecule orbital/ion orbital), s/p z and 2 z s/d cati- on orbital interactions, the maximum region becomes sloped, which is caused by a large overlap of the orbitals due to their shape (σ-bond formation), lowering the binding energy value. When the solvent sorbitals are combined with the xy d and xz d orbitals of the ions, rather weak π-bonds are formed. In case of the solvent p-orbitals, similar trends are observed for p x /p z and p z / 2 z d and, to a lesser extent, for p z /d xz and p x /p x . The steeper slope of p z /d xz and p x /p x compared to s/p x , etc. is explained by the larger extent of the p-orbital compared to the s-orbital, which results in a strong overlap and a decrease in the E bind value. The specific shape of p z / 2 z d is caused by the orientation of p z -orbital directly towards the point charge of the ion. As a result, the contribution of the H ne operator makes the bond stronger.