The structure of small lead clusters

TL;DR

This study determines the lowest-energy structures of small lead clusters up to 160 atoms, revealing non-fcc geometries and identifying high-symmetry magic number clusters, challenging previous assumptions about their structure.

Contribution

First comprehensive computational analysis of lead cluster structures up to 160 atoms using a glue potential, showing non-fcc arrangements and highlighting the significance of high-symmetry clusters.

Findings

Most clusters with fewer than 40 atoms are decahedral or hexagonal close-packed.

Clusters larger than 40 atoms do not follow common structural forms but still include high-symmetry magic number clusters.

The 148-atom D3d hexagonal barrel is a prominent stable structure.

Abstract

We have located the global minimum for all lead clusters with up to 160 atoms using a glue potential to model the interatomic interactions. The lowest-energy structures are not face-centred cubic as suggested previously. Rather, for N<40 the majority of structures are decahedral or hexagonal close-packed, and beyond this size the structures do not correspond to any of the structural forms commonly found in clusters. However, these latter clusters are not simply disordered. High symmetry, magic number clusters are still present, the most prominent of which is the 148-atom D3d hexagonal barrel. We relate these structural preferences back to the form of the interactions.