Structural diversity and the role of particle shape and dense fluid behavior in assemblies of hard polyhedra

TL;DR

This study explores how particle shape influences the self-assembly and structural diversity of hard polyhedra, revealing high propensity for complex crystalline phases driven solely by entropy.

Contribution

It demonstrates the extensive structural diversity and high self-assembly propensity of convex polyhedra based on shape, extending understanding of entropy-driven crystallization.

Findings

Identified 22 crystalline phases including complex crystals and glasses.

Showed shape and local order predict the resulting structure.

Observed unprecedented diversity in non-atomic systems.

Abstract

A fundamental characteristic of matter is its ability to form ordered structures under the right thermodynamic conditions. Predicting these structures - and their properties - from the attributes of a material's building blocks is the holy grail of materials science. Here, we investigate the self-assembly of 145 hard convex polyhedra whose thermodynamic behavior arises solely from their anisotropic shape. Our results extend previous works on entropy-driven crystallization by demonstrating a remarkably high propensity for self-assembly and an unprecedented structural diversity, including some of the most complex crystalline phases yet observed in a non-atomic system. In addition to 22 Bravais and non-Bravais crystals, we report 66 plastic crystals (both Bravais and topologically close-packed), 21 liquid crystals (nematic, smectic, and columnar), and 44 glasses. We show that from simple measures of particle shape and local order in the disordered fluid, the class of ordered structure can be predicted.