Physical embedding machine learning force fields for organic systems

Abstract

Machine learning force fields possess unprecedented potential in achieving both accuracy and efficiency in molecular simulations. Nevertheless, their application in organic systems is often hindered by structural collapse during simulation and significant deviations in the prediction of macroscopic properties. Here, two physics-embedded strategies are introduced to overcome these limitations. First, a physics-inspired self-adaptive bond-length sampling method achieves long-timescale stable simulations by requiring only several tens of single-molecule data sets, and has been validated across molecular systems, including engineering fluids, polypeptides, and pharmaceuticals. Second, a top-down intermolecular correction strategy based on a physical equation is introduced. This strategy requires only a small amount of simulation data and completes the optimization of tunable parameters within a few hours on a single RTX 4090 GPU, significantly reducing errors in density and viscosity, as validated in systems including ethylene carbonate, ethyl acetate, and dimethyl carbonate. Together, these approaches directly integrate physical insights into the machine learning models, thereby enhancing robustness and generalizability, and providing a scalable pathway for physics-embedded machine learning force fields.