The relationship between molecular rotation, structure, material properties, and temperature in plastic crystals is not well understood, meriting further studies. In particular, molecular dynamic (MD) simulations can yield valuable insight for this material class. However, the interplay of short-and long-range interactions, and the structure dependency of piezoelectric properties, calls for the usage of MD based on accurate DFT calculations to capture the temperature-dependent piezoelectric properties and the coupling of molecular rotations of the plastic ionic molecular crystals.