Modified Lorentz oscillator on modeling the dielectric function of Si and Ge Zhenfei Li, Liping Zhang, Yinuo Zhou, Honghua Zhang, Haodong Cheng, Fanying Meng, Wenzhu Liu and Zhengxin Liu Eur. Phys. J. Plus, 140 4 (2025) 293 Published online: 10 April 2025 DOI: 10.1140/epjp/s13360-025-06201-7