Their study shows smaller cations interact more strongly with the ILs than larger ones. In another article, they reported the solvation of similar Ln 3+ cations in three different ILs, based on 1-methyl-3butylimidazolium (BMI + ) and tributylmethylammonium (MeBu3N + ) cations with thiocyanate (SCN -) anions. The first coordination sphere is filled with SCN -anions having CN between 6-8, and the first shell is surrounded by 13-14 BMI + or 8-9 MeBu3N + cations. Here also, the greater interaction of ILs with the smaller lanthanide over the larger one is shown from the charge calculation, as the charge of the metal center decreases from La>Eu>Yb. Olea et al. investigated the selective solvent extraction of La(III) and Ce(III) in two different ionic liquids as dilutants using β-diketone as the extractant using quantum mechanics and Conductor-like Screening Model for Real Solvent (COSMO-RS) calculations.