Inverse Design of Multicomponent Assemblies

TL;DR

This paper extends inverse design via relative entropy optimization to create isotropic interactions for multicomponent self-assembly, enabling the design of complex binary crystal structures with insights into interaction roles.

Contribution

It introduces an extended inverse design method for multicomponent systems and compares the roles of self and cross interactions in assembly.

Findings

Self interactions act as a primer for particle positioning.

Cross interactions refine and lock the structure.

Complex structures require optimization of both interaction types.

Abstract

Inverse design can be a useful strategy for discovering interactions that drive particles to spontaneously self-assemble into a desired structure. Here, we extend an inverse design methodology--relative entropy optimization--to determine isotropic interactions that promote assembly of targeted multicomponent phases, and we apply this extension to design interactions for a variety of binary crystals ranging from compact triangular and square architectures to highly open structures with dodecagonal and octadecagonal motifs. We compare the resulting optimized (self and cross) interactions for the binary assemblies to those obtained from optimization of analogous single-component systems. This comparison reveals that self interactions act as a `primer' to position particles at approximately correct coordination shell distances, while cross interactions act as the `binder' that refines and locks the system into the desired configuration. For simpler binary targets, it is possible to successfully design self-assembling systems while restricting one of these interaction types to be a hard-core-like. However, optimization of both self and cross interaction types appears necessary to design for assembly of more complex or open structures.