Landscape of kinetically trapped binary assemblies

TL;DR

This paper presents an analytical framework for understanding the structure of inherent structure diagrams in two-component assemblies, revealing how a single order parameter determines the apportionment into distinct plateaux and characterizes the morphology of trapped structures.

Contribution

It introduces a novel analytical approach to explain the apportionment of ISDs into plateaux using a single order parameter and characterizes local structure properties within each plateau.

Findings

ISD apportionment is governed by a single unitless order parameter

Analytical framework predicts morphology and structure within ISD plateaux

Framework aids in designing robust nonequilibrium assemblies

Abstract

For two-component assemblies, an inherent structure diagram (ISD) is the relationship between set inter-subunit energies and the types of kinetic traps (inherent structures) one may obtain from those energies. It has recently been shown that two-component ISDs are apportioned into regions or plateaux within which inherent structures display uniform features (e.g., stoichometries and morphologies). Interestingly, structures from one of the plateaux were also found to be robust outcomes of one type of non-equilibrium growth, which indicates the usefulness of the two-component ISD in predicting outcomes of some types of far-from-equilibrium growth. However, little is known as to how the ISD is apportioned into distinct plateaux. Also, while each plateau displays classes of structures that are morphologically distinct, little is known about the source of these distinct morphologies. This article outlines an analytic treatment of the two-component ISD, and shows that the manner in which any ISD is apportioned arises from a single unitless order parameter. Additionally, the analytical framework allows for the characterization of local properties of the trapped structures within each ISD plateau. This work may prove to be useful in the design of novel classes of robust nonequilibrium assemblies.