2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/153187In atomic nuclei, ordered and chaotic states generally coexist. In this paper the transition from ordered to chaotic states will be discussed in the framework of roto-vibrational and shell models. In particular for $^{160}Gd$, in the roto-vibrational model, the Poincarè sections clearly show the transition from order to chaos for different values of rotational frequency. Furthermore, the spectral statistics of low-lying states of several $fp$ shell nuclei are studied with realistic shell-model calculations.Latex, 10 pages, invited talk of Prof. V.R. Manfredi to the International Symposium on Large-Scale Collective Motion of Atomic Nuclei, October 1996, Brolo (Messina), to be published in the Proceedings (World Scientific, Singapore)Nuclear TheoryChaotic Dynamicstext