Theoretical models for electronic stopping in the medium velocity region ∼ are based on a statistical treatment of the atoms. Thus, effects due to the electronic shell structure of the target atom cannot be reproduced. Stopping measurements of fission fragments reveal a pronounced nonmonotonic dependence on Z2. An attempt was made to determine the systematics of the Z2 oscillations in the stopping of fission fragments. After performing a sensitivity analysis of a large number of experimental results, a semiempirical modified Lindhard-Scharff-Schiøtt (LSS) expression for the calculation of fission-fragment ranges in any target material was developed, which includes the Z2 oscillations. This expression has been evaluated and compared to the original LSS theory by means of the Theory of Information.