A comparative study of structural, electronic, and optical properties of thiolated gold clusters with icosahedral vs face-centered cubic cores

The structural, electronic, and optical properties of the protected Au clusters with icosahedral (Ih) face-centered cubic (FCC)-like Au13 cores were studied to understand origin difference in gaps these clusters. It has been demonstrated that choice density functionals does not qualitatively affect Au23 Au25 Ih FCC cores. states, molecular orbitals, natural charges analyzed detail using B3LYP functional. substantial energy lowest-energy absorption peaks for is attributed central atoms (Auc) cores, former which more negative than latter. Natural population analysis demonstrates excess charge Auc atom occupies 6p atomic orbitals. This smaller size core compared core, as a less bulky ligand allows increased electron density, which, turn, increases highest occupied orbital decreases gap.