Different properties accessible by atomistic simulation have been be monitored to determine the atomistic glass transition temperature (aTg) of polymer since the initial work of Rigby et al.[1]. However, atomistic dilatometry is still the more common practice. So in this poster we will present how to implement a consistent protocol with LAMMPS MedeA® GUI and some applications of atomistic dilatometry relevant for engineering applications. Comparison with experimental results will be provided and discussed for Polystyrene.