Photoabsorption spectrum of the Xe@C$_{60}$ endohedral fullerene

TL;DR

This study uses TDDFT to analyze the photoabsorption spectrum of Xe@C60, confirming experimental peaks and suggesting calibration adjustments based on theoretical results.

Contribution

The paper applies a TDDFT approach with the Lanczos algorithm to accurately compute the photoabsorption spectrum of Xe@C60, providing insights into experimental underestimations.

Findings

Confirmed main peaks in the spectrum matching recent measurements.

Identified underestimation of photoionization cross section in experiments.

Suggested using theoretical data at 22 eV for experimental calibration.

Abstract

Photoabsorption spectrum of the Xe@C$_{60}$ endohedral fullerene has been studied using the time-dependent-density-functional-theory (TDDFT), which represents the dynamical polarizability of an interacting electron system by an off-diagonal matrix element of the resolvent of the Liouvilliam superoperator and solves the problem with the Lanczos algorithm. The method has been tested with the photoabsorption cross sections of the free Xe atom and C$_{60}$ fullerene. The result for the Xe@C$_{60}$ confirms the three main peaks observed in the recent measurement in the energy region of the Xe 4$d$ giant resonance and demonstrates the underestimation of the photoionization cross section by the experiment. It is suggested to use the current theoretical result around 22 eV to calibrate the experimental data.