In summary, we have investigated the spectral evolution of sulfur/1,3-diisopropenylbenzene (S/DIB) copolymers as a function of depth of discharge by performing ab initio finitetemperature Raman spectrocopy simulations. The focus has been set on the spectroscopic fingerprints arising from local S/DIB structures containing low and high sulfur content, corresponding to short and long sulfur chains, respectively. This study, to the best of our knowledge, represents the first attempt toward quantum-chemical simulation of operando