computational physics

A fast summation method for the DFT-D3 dispersion correction

arXiv:2607.15103

summary

The paper introduces FourierD3, a low‑rank decomposition technique that restores separability in the DFT‑D3 dispersion correction, enabling fast particle‑mesh evaluation in O(N log N) time without a real‑space cutoff.

Abstract

The DFT-D3 dispersion correction is routinely added to machine learning force fields (MLFFs) trained on dispersion-deficient functionals such as PBE. Its environment-dependent pair coefficients, however, break the atom-centered separability that fast summation methods require, forcing practitioners either to truncate D3 or to accept a substantial slowdown. We introduce FourierD3, a method that uses a functional low-rank decomposition to restore this separability and enable particle-mesh evaluation in time without a real-space cutoff on the dispersion sum.

Topics & keywords

#dispersion correction#density functional theory#fast summation#particle-mesh methods#low-rank decompositionDFT-D3FourierD3O(N log N)particle‑mesh evaluationmachine learning force fieldsfunctional decomposition