Energy-dependent diffusion in a soft periodic Lorentz gas S. Gil-Gallegos, R. Klages, J. Solanpää and E. Räsänen Eur. Phys. J. Special Topics, 228 1 (2019) 143-160 Published online: 30 May 2019 DOI: 10.1140/epjst/e2019-800136-8