Accurate Hellmann–Feynman forces from density functional calculations with augmented Gaussian basis sets

Journal Article · Wed Jan 04 00:00:00 EST 2023 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/5.0130668· OSTI ID:1907725

Pathak, Shivesh ; López, Ignacio Ema ; Lee, Alex J.; Bricker, William P. ; Fernández, Rafael López ; Lehtola, Susi ; Rackers, Joshua A.

The Hellmann–Feynman (HF) theorem provides a way to compute forces directly from the electron density, enabling efficient force calculations for large systems through machine learning (ML) models for the electron density. The main issue holding back the general acceptance of the HF approach for atom-centered basis sets is the well-known Pulay force which, if naively discarded, typically constitutes an error upward of 10 eV/Å in forces. In this work, we demonstrate that if a suitably augmented Gaussian basis set is used for density functional calculations, the Pulay force can be suppressed, and HF forces can be computed as accurately as analytical forces with state-of-the-art basis sets, allowing geometry optimization and molecular dynamics to be reliably performed with HF forces. Our results pave a clear path forward for the accurate and efficient simulation of large systems using ML densities and the HF theorem.

• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: NA0003525
• OSTI ID: 1907725
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Vol. 158 Journal Issue: 1; ISSN 0021-9606
• Publisher: American Institute of Physics
• Country of Publication: United States
• Language: English