Photoionization of C₆₀: a model study

Time-dependent density functional theory is used to calculate the total and subshell photoionization cross sections of C₆₀. The core of 60 C⁴⁺ ions is smeared into a classical jellium shell before treating the correlated motion of the 240 valence electrons quantum mechanically. The calculation reveals two collective plasmon resonances in the total cross section in agreement with the experiment. It is found that a phase-coherent superposition of amplitudes leading to enhancements in the ionization from various C₆₀ subshells in two distinct energy regions essentially builds the plasmons. While the result shows good qualitative agreement with the experiments, the limitation of the model to describe the data in quantitative detail is discussed.