Rattling atoms induced ultralow thermal conductivity and high thermoelectric performance in monolayer Ca3Sn2S7 chalcogenide perovskiteWenfeng Li, Huihui Wang, Zhiyong Liu and Gui YangEur. Phys. J. Plus, 140 1 (2025) 12DOI: https://doi.org/10.1140/epjp/s13360-025-05973-2