On the compression of the fullerene shell by an extra positive charge at its center

TL;DR

This paper studies how adding a positive charge at the center of a fullerene shell affects its potential and photoionization properties, revealing that monopole polarization does not influence photoionization cross sections.

Contribution

It introduces a model for the fullerene shell potential considering monopole polarization and demonstrates its effects on photoionization, showing polarization's negligible impact on cross sections.

Findings

Monopole polarization varies with the positive charge at the center.

Proper potential models should have a non-flat bottom.

Monopole polarization does not affect photoionization cross sections.

Abstract

In this Letter, we investigate the variation of endohedral A@CN potential due to addition at the center of it a positive charge, for example, in the process of atom A photoionization. Using a reasonable model to describe the fullerenes shell, we managed to calculate the variation that is a consequence of the monopole polarization of CN shell. We analyze model potentials with flat and non-flat bottoms and demonstrate that the phenomenological potentials that properly simulates the C60 shell potential should belong to a family of potentials with a non-flat bottom. As concrete example, we use the Lorentz-bubble model potential. By varying the thickness of this potential, we describe the various degrees of the monopole polarization of the C60 shell by positive electric charge in the center of the shell. We calculated the photoionization cross-sections of He, Ar and Xe atoms located at the center of C60 shell with and without taking into account accompanying this process monopole polarization of the fullerenes shell. Unexpectedly, we found that the monopole polarization do not affect the photoionization cross sections of these endohedral atoms.