A neural network potential with rigorous treatment of long-range dispersion

Abstract

Neural Network Potentials (NNPs) have quickly emerged as powerful computational methods for modeling large chemical systems with the accuracy of quantum mechanical methods but at a much smaller computational cost. To make the training and evaluation of the underlying neural networks practical, these methods commonly cut off interatomic interactions at a modest range (e.g., 5.2 Å), so longer-range interactions like London dispersion are neglected. This limits the accuracy of these models for intermolecular interactions. In this work, we develop a new NNP designed for modeling chemical systems where dispersion is an essential component. This new NNP is extended to treat dispersion interactions rigorously by calculating atomic dispersion coefficients through a second set of NNs, which is trained to reproduce the coefficients from the quantum-mechanically derived exchange-hole dipole moment (XDM) model. The NNP with this dispersion correction predicts intermolecular interactions in very good agreement with the QM data, with a mean absolute error (MAE) of 0.67 kcal mol⁻¹ and a coefficient of determination (R²) of 0.97. The dispersion components of these intermolecular interactions are predicted in excellent agreement with the QM data, with a mean absolute error (MAE) of 0.01 kcal mol⁻¹ and an R² of 1.00. This combined dispersion-corrected NNP, called ANIPBE0-MLXDM, predicts intermolecular interaction energies for complexes from the DES370K test set with an MAE of 0.69 kcal mol⁻¹ and an R² of 0.97 relative to high-level ab initio results (CCSD(T)), but with a computational cost that is billions of times smaller. The ANIPBE0-MLXDM method is effective for simulating large-scale dispersion-driven systems, such as molecular liquids and gas adsorption in porous materials, on a single computer workstation.