Ab initio phonon-coupled nonadiabatic relaxation dynamics of [Au25(SH)18]− clusters

Nanoscale gold clusters exhibit unique electronic and optical properties. Here, we study the excited state dynamics and electron–phonon coupling of [Au25(SH)18]– nanoclusters by using quantum-classical molecular dynamics combined with time-dependent density-functional theory. Our result reproduces the experimental measurements and provides further insights into the relaxation dynamics of ligand protected gold clusters. We examine the ultrafast electronic dynamics induced by specific phonon modes. The roles of the Au13 core and Au12 ring in the optical process are investigated. We find that the LUMO–HOMO transition is dominated by AuAu stretching of the Au13 core, whereas the LUMO + 1 − HOMO transition is induced by breathing vibrations of the Au core as well as AuS stretching. We clarify the interplay between electron–phonon couplings and specific energy-transfer processes in [Au25(SH)18]– nanoclusters.