Some fundamental problems for an energy conserving adaptive resolution molecular dynamics scheme

TL;DR

This paper investigates the fundamental issues in designing energy-conserving adaptive resolution molecular dynamics schemes, highlighting the conceptual problems with potential energy-based approaches that challenge their robustness.

Contribution

The work identifies core conceptual problems with potential energy-based adaptive resolution schemes in classical MD, suggesting force-based methods are more viable.

Findings

Potential energy-based schemes face fundamental conceptual issues.

Force-based adaptive resolution methods are more promising.

Challenges hinder the development of robust energy-conserving adaptive MD algorithms.

Abstract

Adaptive resolution molecular dynamics (MD) schemes allow for changing the number of degrees of freedom on the fly and preserve the free exchange of particles between regions of different resolution. There are two main alternatives on how to design the algorithm to switch resolution using auxiliary ''switching'' functions; force based and potential energy based approach. In this work we show that, in the framework of classical MD, the latter presents fundamental conceptual problems which make unlikely, if not impossible, the derivation of a robust algorithm based on the potential energy.