Associative bond swaps in molecular dynamics

TL;DR

This paper introduces a three-body potential for associative bond swaps in molecular dynamics, implemented in HOOMD-blue, which enhances simulation efficiency and models adaptive network materials without topology changes.

Contribution

It presents a novel three-body potential for bond swaps in molecular dynamics, enabling efficient simulation of adaptive networks like vitrimers within HOOMD-blue.

Findings

Associative bond swaps accelerate system equilibration.

The method models slip-bond behavior naturally.

Potential for broader application in simulation efficiency.

Abstract

We implement a three-body potential to model associative bond swaps, and release it as part of the HOOMD-blue software. The use of a three-body potential to model swaps has been proven to be effective and has recently provided useful insights into the mechanics and dynamics of adaptive network materials such as vitrimers. It is elegant because it can be used in plain molecular dynamics simulations without the need for topology-altering Monte Carlo steps, and naturally represents typical physical features such as slip-bond behavior. It is easily tunable with a single parameter to control the average swap rate. Here, we show how associative bond swaps can be used to speed up the equilibration of systems that self-assemble by avoiding traps and pitfalls, corresponding to long-lived metastable configurations. Our results demonstrate the possibilities of these swaps not only for modeling systems that are associative by nature, but also for increasing simulation efficiency in other systems that are modellable in HOOMD-blue.