In this study, we tested the MD system by simulating erlotinib, an EGFR inhibitor, in water under the microcanonical ensemble (NVE, i.e. constant number of particles, volume and total energy of the system). The system contains 151 atoms (Figure ), with 52 belonging to erlotinib, defined as the ML region, while the remaining 99 atoms belonging to 33 water molecules. In this configuration, the ML region constitutes approximately 34.4% of the system's atoms, allowing us to observe its influence on the total energy contribution as fully as possible.