Efficient method to calculate total energies of large nanoclusters

TL;DR

This paper introduces a first-principles based approach to efficiently estimate the total energies of large nanoclusters by separating contributions from surface, edge, corner, and bulk regions, enabling analysis of complex polyhedral structures.

Contribution

The paper presents a novel method combining first-principles calculations with energy separation to accurately estimate total energies of large nanoclusters, including non-stoichiometric and polar surface cases.

Findings

Effective energy separation for large clusters.

Minimal relaxation effects in Cu clusters.

Significant surface and edge variations in CdSe clusters.

Abstract

We present an approach to calculate total energies of nanoclusters based on first principles estimates. For very large clusters the total energy can be separated into surface, edge and corner energies, in addition to bulk contributions. Using this separation and estimating these with direct, first principles calculations, together with the relevant chemical potentials, we have calculated the total energies of Cu and CdSe tetrahedrons containing a large number of atoms. In our work we consider polyhedral clusters so that in addition our work provides direct information on relaxation. For Cu the effects are very small and the clusters vary uniformly from very small to very large sizes. For CdSe there are important variations in surface and edge structures for specific sizes; nevertheless, the approach can be used to extrapolate to large non-stoichiometric clusters with polar surfaces.