Corps, Angel L.Relaño Pérez, Armando2023-06-162023-06-162020-02-282470-004510.1103/PhysRevE.101.022222https://hdl.handle.net/20.500.14352/6193©2020 American Physical Society. We acknowledge financial support through Spanish Grants No. PGC2018-094180-B-I00 (MCIU/AEI/FEDER, EU) and No. FIS2015-63770-P (MINECO/FEDER, EU).Theoretical expressions for the distribution of the ratio of consecutive level spacings for quantum systems with transiting dynamics remain unknown. We propose a family of one-parameter distributions P(r) P(r; beta), where beta is an element of [0, +infinity) is a generalized Dyson index, that describes the eigenlevel statistics of a quantum system characterized by different symmetries and degrees of chaos. We show that this crossover strongly depends on the specific properties of each model, and thus the reduction of such a family to a universal formula, albeit desirable, is not possible. We use the information entropy as a criterion to suggest particular ansatze for different transitions, with a negligible associated error in the limits corresponding to standard random ensembles.engjournal articlehttps://doi.org/10.1103/PhysRevE.101.022222https://journals.aps.org/open access536Gaudin modelsQuantumStatisticsHermiteTermodinámica2213 Termodinámica