Microsolvation of a cation in helium quantum solvent is an attractive phenomenon leading generally to the formation of a strongly packed structure known as ‘Snowball’ feature. Here, the lowest energy structures and the relative stability of the solvated potassium cation K⁺ in helium clusters K⁺He_n up to the size n = 20 are investigated employing Density Functional Theory (DFT) and pairwise methods. The DFT calculations showed that M05–2X/6–311++G (3df, 2p) level of theory can reproduce properly the experimental data of K⁺He diatomic potential, whereas, in the pairwise method, the Basin-Hopping Monte Carlo (BHMC) algorithm was applied for the global optimization. The remarkable differences in the lowest energy structures computed in the frame of both methods are shown for K⁺He₁₁ and K⁺He₁₂ clusters. The BHMC optimization converged to an icosahedral geometry for n = 12, corresponding to the highest value of the binding energy per atom. For both methods, we have concluded that the first solvation shell is completed at the size n = 15, despite the maximum packing structure obtained at n = 17. Finally, the stability of the potassium doped helium cluster is discussed based on the Density Of States (DOS) curves.

阳离子在氦量子溶剂中的微溶剂化是一种引人注目的现象，通常会导致形成称为“雪球”特征的强堆积结构。在这里，使用密度泛函理论（DFT）和成对方法研究了最大n = 20的氦团簇K ⁺ He _n中的最低能级结构和溶剂化钾阳离子K ⁺的相对稳定性。DFT计算表明，M05–2X / 6–311 ++ G（3df，2p）理论水平可以正确再现K ⁺的实验数据。他具有双原子势能，而在成对方法中，应用了Basin-Hopping Monte Carlo（BHMC）算法进行全局优化。对于K ⁺ He ₁₁和K ⁺ He ₁₂簇，在两种方法的框架中计算出的最低能量结构存在显着差异。对于n = 12，BHMC优化收敛到二十面体几何，对应于每个原子的结合能的最大值。对于这两种方法，我们都得出结论，尽管在n = 17处获得了最大的堆积结构，但第一个溶剂化壳的尺寸为n = 15，但最终，基于态密度讨论了掺杂钾的氦团簇的稳定性。 （DOS）曲线。