  This comprehensive study delves into the intricate interplay between protons
and organic polymers, offering insights into proton therapy in cancer
treatment. Focusing on the influence of the spatial electron density
distribution on stopping power estimates, we employed time-dependent density
functional theory (TDDFT), coupled with the Penn method. Surprisingly, the
assumption of electron density homogeneity in polymers is fundamentally flawed,
resulting in an overestimation of stopping power values at energies below 2
MeV, approximately. Moreover, Bragg's rule application in specific compounds
exhibited significant deviations from experimental data in the Bragg peak
region, challenging established norms.
