MACE: Higher Order Equivariant Message Passing Neural Networks for Fast and Accurate Force Fields

TL;DR

MACE introduces higher order message passing in equivariant neural networks, significantly improving speed and accuracy of force field predictions in chemistry and materials science.

Contribution

The paper presents MACE, a novel equivariant MPNN that uses four-body messages to enhance expressivity and reduce message passing iterations, improving efficiency and accuracy.

Findings

Achieves state-of-the-art accuracy on benchmark datasets.

Reduces message passing iterations to just two.

Improves learning curve steepness.

Abstract

Creating fast and accurate force fields is a long-standing challenge in computational chemistry and materials science. Recently, several equivariant message passing neural networks (MPNNs) have been shown to outperform models built using other approaches in terms of accuracy. However, most MPNNs suffer from high computational cost and poor scalability. We propose that these limitations arise because MPNNs only pass two-body messages leading to a direct relationship between the number of layers and the expressivity of the network. In this work, we introduce MACE, a new equivariant MPNN model that uses higher body order messages. In particular, we show that using four-body messages reduces the required number of message passing iterations to just two, resulting in a fast and highly parallelizable model, reaching or exceeding state-of-the-art accuracy on the rMD17, 3BPA, and AcAc benchmark tasks. We also demonstrate that using higher order messages leads to an improved steepness of the learning curves.