Favoured Local Structures in Liquids and Solids: a 3D Lattice Model

TL;DR

This study introduces a 3D lattice model to explore how Favoured Local Structures influence the properties of liquids and solids, revealing patterns in crystal formation, packing, and metastability related to local geometry.

Contribution

The paper presents a novel lattice spin model allowing arbitrary FLS selection on an FCC lattice, systematically analyzing their impact on crystalline and liquid behaviors.

Findings

Low symmetry FLSs lead to larger crystal unit cells.

Chiral FLSs show poor packing properties.

FLS accumulation in supercooled liquids correlates with large unit cells.

Abstract

We investigate the connection between the geometry of Favoured Local Structures (FLS) in liquids and the associated liquid and solid properties. We introduce a lattice spin model - the FLS model on a face-centered cubic lattice - where this geometry can be arbitrarily chosen among a discrete set of 115 possible FLS. We find crystalline groundstates for all choices of a single FLS. Sampling all possible FLS's, we identify the following trends: i) low symmetry FLS's produce larger crystal unit cells but not necessarily higher energy groundstates, ii) chiral FLS's exhibit to peculiarly poor packing properties, iii) accumulation of FLS's in supercooled liquids is linked to large crystal unit cells, and iv) low symmetry FLS's tend to find metastable structures on cooling.