2025/06/12 by Florian Foitzik, Massimiliano Bartolomei, José Campos-Martı́nez +8 · 1 voice
Materials Science · Physics and Astronomy · #Advanced Chemical Physics Studies #Hydrogen Storage and Materials #Quantum, superfluid, helium dynamics
paper · pdf · doi:10.1002/sstr.202500094
openalex publication_date 2025/06/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
In this article, the results of a combined experimental and theoretical investigation which provides evidence of the existence of large well‐ordered structures of helium atoms in He N Ho 2+ and He N Bi 2+ clusters. In particular, we observe up to four shells of helium surrounding the metallic dication for He 74 Ho 2+ in a sequence from inside to outside of: an icosahedron; a dodecahedron; an icosahedron and finally an icosidodecahedron. While these results confirm our previous study for He N Ca 2+ , for He N Bi 2+ , the mass spectra exhibit different magic numbers ( N = 14, 38, 52 and 90). Evaporation energies calculated by means of classical minimization and Monte Carlo simulations confirm the existence of Mozartkugel‐like structures compatible with the features observed experimentally. Thus, He 90 Bi 2+ , the largest of these clusters ever observed exhibiting ordered solvation arrangements, would be formed by the following sequence of concentric ordered structures: a bicapped hexagonal antiprism (BHA) with the first 14 He atoms; a tetradecahedron with 24 atoms, another BHA and, finally, the last 38 He atoms form a pentagonal icositetrahedron. The formation of these large ordered shells seems the result of a delicate balance between the He–Bi 2+ and He–He equilibrium distances besides a sufficiently strong He–Bi 2+ interaction potential.