Complete neural initialization speeds up materials density calculations

Complete Neural Electronic Initialization Accelerates Materials DFT

Machine Learning

Summary

Calculating the properties of materials at the atomic level is very slow because it needs to figure out how electrons behave. The authors found that previous AI methods for speeding this up missed important details. They created new models that include these missing parts and can start the calculations from scratch without extra information. This new approach speeds up the calculations by about a quarter while keeping results accurate.

What this means in practice

Authors

Felix Ærtebjerg, Jonas Elsborg, Arghya Bhowmik

Abstract

We present the first complete machine learning method for accelerating plane-wave density functional theory (DFT) in materials under the projector augmented wave (PAW) formalism. We formalize seven criteria that a \textit{Complete Neural Electronic Initializer} must satisfy for practical end-to-end PAW DFT acceleration. Applying these criteria to prior work reveals two missing structure-dependent components, augmentation occupancies and spin initialization, that prevent existing methods from providing complete reference-free initialization. Controlled ablations show that omitting these components can eliminate or reverse the acceleration obtained via models that only predict the smooth valence density. We satisfy these missing requirements by introducing AugNet, the first general equivariant model for PAW augmentation occupancies, and the first general spin density model for materials, which predicts the smooth spin-difference density and spin-difference PAW augmentation occupancies using predicted magnetic moments to constrain the global magnetic state. Combined with existing valence density models, these components satisfy all seven criteria and form a fully reference-free electronic initializer for materials DFT, requiring no electronic quantities from a converged target calculation. Our method reduces end-to-end DFT wall time by up to ~25% on unseen structures while preserving converged energies.