Cluster-surface and cluster-cluster interactions: Ab initio calculations and modeling of van der Waals forces

TL;DR

This paper presents ab initio calculations of van der Waals forces between silicon nanostructures and surfaces, providing models for efficient simulation of large systems in nanotechnology.

Contribution

It introduces efficient ab initio methods and simple models for calculating van der Waals interactions in large silicon nanostructures and surfaces, enabling faster molecular dynamics simulations.

Findings

Calculated van der Waals coefficients for silicon clusters and surfaces.

Developed simple models for large-scale nanostructure interactions.

Validated models with ab initio data for accurate simulations.

Abstract

We present fully ab-initio calculations of van der Waals coefficients for two different situations: i) the interaction between hydrogenated silicon clusters; and ii) the interactions between these nanostructures and a non metallic surface (a silicon or a silicon carbide surface). The methods used are very efficient, and allow the calculation of systems containing hundreds of atoms. The results obtained are further analyzed and understood with the help of simple models. These models can be of interest for molecular dynamics simulations of silicon nanostructures on surfaces, where they can give a very fast yet sufficiently accurate determination of the van der Waals interaction at large separations.