Diffusion Monte Carlo with fictitious masses finds holes in potential energy surfaces

Abstract

Holes are commonly associated with high-dimensional, non-parametric representations of potential energy surfaces (PESs). These are regions of the PES with large negative values. Typically these occur at highly distorted geometries of (in reality) high energy. Finding holes in a systematic and efficient way is thus an important aspect in the development of PESs. Here we propose using diffusion Monte Carlo (DMC) with artificially reduced masses to automatically and robustly sample large regions of a fit, including those at very high energies. We demonstrate this for a recent PES of methane that was obtained using energies and gradients. The DMC software with the methane potential is available for download.

GRAPHICAL ABSTRACT

Acknowledgements

JMB thanks the Army Research Office, DURIP grant (W911NF-14-1-0471), for funding a computer cluster where the calculations were performed.

Disclosure statement

No potential conflict of interest was reported by the author(s).