A double exponential Morse potential energy function for diatomic molecules Changyi He, Zhixiang Fan, Hongrui Tian, Qunchao Fan, Huidong Li, Jia Fu and Feng Xie Eur. Phys. J. Plus, 140 5 (2025) 370 Published online: 07 May 2025 DOI: 10.1140/epjp/s13360-025-06317-w