Icosahedron magic -- New forms of the most spherical Platonic solid
Riccardo Ferrando, Dipartimento di Fisica, Università di Genova.
The icosahedron is the Platonic solid that combines the highest degree of symmetry with the most compact shape in terms of surface-to-volume ratio. Icosahedral structures are very common in nature, being observed in nanoparticles, viruses, protein and DNA aggregates, intermetallic compounds and quasicrystals. In spite of their presence in such a wide variety of domains, a general theoretical framework for constructing icosahedra starting from discrete particles is still lacking. After a general introduction to Platonic solids and to their realizations in nanoscale physical systems [1,2], we present a new general method for constructing icosahedral aggregates [3] that combines ideas from solid-state crystallography and virus biology. We demonstrate that icosahedra can be constructed as sequences of concentric shells that are mapped into paths running in the two-dimensional hexagonal lattice. Our method allows to combine chiral and achiral shells in the same structure. The method is applied to the bottom-up design of metal clusters and nanoparticles.
[1] Y. Xia, D. Nelli, R. Ferrando, J. Yuan, Z.Y. Li, Nature Communications 12, 3019 (2021)
[2] D. Nelli, C. Roncaglia, R. Ferrando, Z. Kataya, Y. Garreau, A. Coati, C. Andreazza-Vignolle, P. Andreazza, Nanoscale 15, 18891 (2023)
[3] N. Canestrari, D. Nelli, R. Ferrando, submitted (2024).
Data: 24 maggio 2024, ore 10:00
Luogo: Aula informatica, DIMA, Sapienza Università di Roma - Via Eudossiana 18, Roma
