π€ AI Summary
Existing machine learning force fields achieve higher accuracy than classical force fields but fail to explicitly encode the temporal continuity of state evolution and the strong prior of structural similarity between adjacent configurations in molecular dynamics. This work introduces, for the first time, a continuous-time evolution prior into equivariant force field design. We propose an implicit equivariant architecture based on Deep Equilibrium Models (DEQs), enabling intermediate feature reuse and implicit gradient computation while preserving SE(3) equivariance and ensuring memory-efficient training. Our method achieves a joint 10β20% improvement in both simulation speed and accuracy on the MD17, MD22, and OC20-200k benchmarks. Moreover, it significantly reduces GPU memory consumption, facilitating training of larger systems and more complex models.
π Abstract
Machine learning force fields show great promise in enabling more accurate molecular dynamics simulations compared to manually derived ones. Much of the progress in recent years was driven by exploiting prior knowledge about physical systems, in particular symmetries under rotation, translation, and reflections. In this paper, we argue that there is another important piece of prior information that, thus fa,r hasn't been explored: Simulating a molecular system is necessarily continuous, and successive states are therefore extremely similar. Our contribution is to show that we can exploit this information by recasting a state-of-the-art equivariant base model as a deep equilibrium model. This allows us to recycle intermediate neural network features from previous time steps, enabling us to improve both accuracy and speed by $10%-20%$ on the MD17, MD22, and OC20 200k datasets, compared to the non-DEQ base model. The training is also much more memory efficient, allowing us to train more expressive models on larger systems.