Conservative adaptive-precision interatomic potentials

TL;DR

This paper introduces a Hamiltonian-based adaptive-precision interatomic potential method that conserves energy and momentum, enabling faster simulations by coupling different potentials while maintaining physical accuracy.

Contribution

It presents a novel Hamiltonian coupling approach for adaptive-precision interatomic potentials, ensuring conservation laws and improving computational efficiency.

Findings

Conservation of energy and momentum verified numerically.

Achieved 10 to 100 times speedup over pure ACE simulations.

Demonstrated effective coupling of EAM and ACE potentials.

Abstract

Adaptive precision molecular dynamics simulations have developed along energy- and force-coupling approaches, which allow for a continuous transition between different particle descriptions or interaction potentials. Most approaches consider different (fixed) spatial regions, which control the transition between the descriptions and consequently avoid a consistent momentum-conserving Hamiltonian description. We present here a new approach to fully integrate the coupling into a Hamiltonian, therefore allowing for a conservative description, which, by design, guarantees both energy and momentum conservation. By coupling a fast EAM potential to a highly accurate ACE potential, we verify numerically the conservation properties and show that one can achieve - dependent on both the potential and the atomistic system - a speedup of one or two orders of magnitude compared to a pure ACE simulation.