Making copper, silver and gold fullerene cages breathe

We show that optical properties change when the fullerene structures of Au-32, Cu-32 and Ag-32 inflate and deflate. We first observe significant differences in the extinction spectra employing a classical approach based on the Green's dyadic method. By means of real-time time-dependent density functional theory. We continue to calculate the optical spectrum (OP) via a delta-kick simulation, comparing results with the ground-state energetic property the HOMO-LUMO (HL) gap. Red-shift of the OP is expected as the fullerenes inflate, with only +/- 10% change in the size. As the fullerene breathes, a 0.8 eV shift in the first peak position could be observed in the gold nanoparticle. Ag has a smoother behaviour than both Au and Cu. We have also found changes in the optical spectra can not be directly interpreted as a result of changes in the HL gap.

Automated summary

This study demonstrates that the optical properties of Au-32, Cu-32, and Ag-32 change when their fullerene structures inflate and deflate. The extinction spectra show significant differences, with a red-shift in the optical spectrum observed as the fullerenes inflate. The changes in the optical spectra cannot be solely attributed to variations in the HOMO-LUMO gap.