Diffusion Monte Carlo description of Cs2(3Σu)-(4He)N clusters: an example of weak dopant-helium interaction

In this paper, we study the energy and geometric properties of Cs-2((3)Sigma(u))-(He-4)(N) clusters, 2 <= N <= 20, N even, through a diffusion Monte Carlo methodology. Considering the results for doped clusters in which the He-impurity interaction dominates over the He-He one, our aim is to investigate the case when this assumption is not fulfilled anymore and the helium-helium potential becomes dominant. We find a scenario where a pure helium subcomplex is formed, leaving out the alkaline dimer, with the largest species gathering the helium atoms in a two-shell-like structure, the first of which is filled with ten particles. Our results are in agreement with previous theoretical and experimental findings.