Green-function method for calculation of adsorption of organic molecules on noble metal nanoparticles

TL;DR

This paper introduces a Green-function based numerical method to analyze the electronic structure and chemical bonding of organic molecules adsorbed on silver nanoparticles, combining density functional theory and scattering theory.

Contribution

It develops a novel Green-function approach for calculating the electronic structure of molecule-nanoparticle systems, incorporating a model of embedded atoms and scattering theory.

Findings

Localized electronic levels split from the nanosystem's band edge.

The method provides insights into chemical bonding characteristics.

Electronic structure details of PIC molecule on silver nanoparticle obtained.

Abstract

A numerical method for calculation electronic structure of a nanosystem composed of a pseudoisocyanine (PIC) molecule assembled on a silver nanoparticle is developed. The electronic structure of the silver nanoparticle containing 125 atoms is calculated within the local density version of the density functional method. A model of an Ag atom embedded in the center of a spherical jellium cluster is used. The host electron Green function is calculated by means of the spherically symmetric expansion. The principal theoretical tool is the scattering theory using the Green function method. The molecule -- silver nanoparticle interaction is studied using the approach similar to that of the Anderson model for transition metal impurities in solids. Localized levels are shown to split off from the top of the band of the nanosystem. The electronic structure calculations yield information on the character of chemical bonding in the PIC molecule --- silver particle nanosystem.