This theoretical study proposes new protocols to construct continuous energy surfaces in many-body quantum systems, ensuring continuity of both energies and states. The approach is illustrated with the asymmetric fission of plutonium 240, where calculations reveal a scission region characterized by a neutron excess in the “neck” connecting the fragments — the final “glue” before the nucleus splits. These results were published in Physical Review Letters: P. Carpentier et al., Phys. Rev. Lett. 133 (2024)