Dynamical screening of an endohedral atom

TL;DR

This paper generalizes the dynamical screening factor for atoms inside fullerenes, considering arbitrary positions and comparing with quantum calculations, highlighting spatial dependence and improving theoretical models.

Contribution

It extends the dynamical screening model to arbitrary atomic positions within fullerenes and incorporates plasmon effects for better quantum agreement.

Findings

Screening factor depends significantly on atom's radial position.

Modified model aligns better with quantum calculations.

Spatial averaging provides a practical approximation.

Abstract

The present work is a generalisation of the dynamical screening factor presented in [1] to consider an atom located at an arbitrary position within the fullerene. A more elaborated investigation into the case where the atom is located at the centre is performed and compared with quantum mechanical calculations for dynamical screening factor of Ar@C$_{60}$ [2] and Mg@C$_{60}$ [3]. The $\pi$ and $\sigma$ plasmons of the fullerene are accounted for in a modified screening factor to improve correspondence with the quantum calculations. The spatial dependence of the screening factor was explored with Ar@C$_{60}$ and Ar@C$_{240}$ and found to depend significantly on the radial distance of the atom from the centre of the fullerene. A spatial averaging of the screening factor is presented.