However, according to our simulations, such dissolution mechanism is prevented when there is no extensive water in the system (Fig. 5b), which may confirm congruent dissolution assumptions by Tsuji et al. [46] in a similar experimental system. One of the reasons why incongruent dissolution is prevented in the BaTiO3/molten hydroxide system is correlated with interactions of sodium and potassium ions with the BaTiO3 surface. Our simulations show that they tend to be adsorbed on Ba site on TiO2 terminated surface while adsorbed on Ti sites on BaO terminated surface. A more detailed investigation of the adsorption mechanism in the BaTiO3–NaOH–KOH interface will be presented in a separate study.