Shadow Molecular Dynamics for a Charge-Potential Equilibration Model

TL;DR

This paper presents a shadow molecular dynamics method based on the ACKS2 charge-potential model, enabling efficient and stable simulations by approximating the energy function and avoiding costly iterative solutions.

Contribution

It introduces a shadow MD scheme that approximates ACKS2's charge-potential energy, improving stability and computational efficiency in molecular dynamics simulations.

Findings

Mitigates overhead of charge and potential calculations.

Provides stable and efficient MD simulations.

Enables high-fidelity physical modeling.

Abstract

We introduce a shadow molecular dynamics (MD) approach based on the Atom-Condensed Kohn-Sham second-order (ACKS2) charge-potential equilibration model. In contrast to regular flexible charge models, the ACKS2 model includes both flexible atomic charges and potential fluctuation parameters that allow for physically correct charge fragmentation and scaling of the polarizability. Our shadow MD scheme is based on an approximation of the ACKS2's flexible charge-potential energy function, in combination with extended Lagrangian Born-Oppenheimer MD. Utilizing this shadow charge-potential equilibration approach mitigates the costly overhead and stability problems associated with finding well-converged iterative solutions to the charges and potential fluctuations of the ACKS2 model in an MD simulation. Our work provides a robust and versatile framework for efficient, high-fidelity MD simulations of diverse physical phenomena and applications.