Energy landscapes, structural topologies and rearrangement mechanisms in clusters of dipolar particles

TL;DR

This paper explores how clusters of particles with combined isotropic and dipolar interactions form complex structures, mapping their energy landscapes and identifying mechanisms for structural rearrangements.

Contribution

It provides a detailed analysis of the energy landscape and rearrangement pathways in dipolar particle clusters with combined interactions.

Findings

Mapping of energy landscapes using disconnectivity graphs.

Identification of rearrangement mechanisms for topological interconversion.

Insights into the influence of dipolar strength on cluster structures.

Abstract

Clusters of spherical particles with isotropic attraction favour compact structures that maximise the number of energetically optimal nearest-neighbour interactions. In contrast, dipolar interactions lead to the formation of chains with a low coordination number. When both isotropic and dipolar interactions are present, the competition between them can lead to intricate knot, link and coil structures. Here, we investigate how these structures may self-organise and interconvert in clusters bound by the Stockmayer potential (Lennard-Jones plus point dipole). We map out the low-lying region of the energy landscape using disconnectivity graphs to follow how it evolves as the strength of the dipolar interactions increases. From comprehensive surveys of isomerisation pathways, we identify a number of rearrangement mechanisms that allow the topology of chain-like structures to interconvert.