Classical molecular dynamics simulations were performed using the GROMACS-2018.3 package 80 at four different temperatures, T(K) = 329, 336, 343, and 358. Acetamide molecules, cations and anions were taken in a ratio that mimicked the compositions employed in the MHz-GHz experiments. For each of the DESs considered, a total of 1000 particles (acetamide + cation + anion) were considered and the overall electroneutrality ensured. Composition of each system is given in Table (supplementary material). OPLS (optimized potentials for liquid simulations) type model force field were used . Since the functional forms and notations associated with different pieces of the OPLS model potential were discussed earlier , these are provided in the Appendix A1 (supplementary material). Interaction parameters developed for correctly reproducing the experimental 𝜀 𝑠 of neat molten acetamide were employed to represent the acetamide molecules. The force-field parameters for Br -, NO3 -, and ClO4 -were used as those available in the relevant literature . Non-bonding parameters of Li + were taken from another work. The cationic charge was scaled as 0.8e in order to be consistent with the anionic charges. Atomic representations of acetamide, cation and anions are shown in Fig. (supplementary material).