Cluster self-assembly condition for arbitrary interaction potentials

TL;DR

This paper derives a mathematical criterion for the formation of cluster phases in systems of particles with arbitrary repulsive interactions, validated by simulations and applicable to various potential shapes.

Contribution

It introduces a general analytical condition for cluster crystal emergence applicable to any interaction potential shape, extending previous bounded potential results.

Findings

The criterion accurately predicts cluster formation in diverse potentials.

Validation against molecular dynamics confirms the criterion's reliability.

The approach generalizes known results to arbitrary repulsive interactions.

Abstract

We present a sufficient criterion for the emergence of cluster phases in an ensemble of interacting classical particles with repulsive two-body interactions. Through a zero-temperature analysis in the low density region we determine the relevant characteristics of the interaction potential that make the energy of a two-particle cluster-crystal become smaller than that of a simple triangular lattice in two dimensions. The method leads to a mathematical condition for the emergence of cluster crystals in terms of the sum of Fourier components of a regularized interaction potential, which can be in principle applied to any arbitrary shape of interactions. We apply the formalism to several examples of bounded and unbounded potentials with and without cluster-forming ability. In all cases, the emergence of self-assembled cluster crystals is well captured by the presented analytic criterion and verified with known results from molecular dynamics simulations at vanishingly temperatures. Our work generalises known results for bounded potentials to repulsive potentials of arbitrary shape.