Relativistic DFT investigation of electronic structure effects arising from doping the Au-25 nanocluster with transition metals


Alkan F. , Munoz-Castro A., Aikens C. M.

NANOSCALE, vol.9, no.41, pp.15825-15834, 2017 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 9 Issue: 41
  • Publication Date: 2017
  • Doi Number: 10.1039/c7nr05214f
  • Title of Journal : NANOSCALE
  • Page Numbers: pp.15825-15834

Abstract

We perform a theoretical investigation using density functional theory (DFT) and time-dependent DFT (TDDFT) on the doping of the Au-25(SR)(18)(-1) nanocluster with group IX transition metals (M = cobalt, rhodium and iridium). Different doping motifs, charge states and spin multiplicities were considered for the single-atom doped nanoclusters. Our results show that the interaction (or the lack of interaction) between the d-type energy levels that mainly originate from the dopant atom and the super-atomic levels plays an important role in the energetics, the electronic structure and the optical properties of the doped systems. The evaluated MAu24(SR)(18)(q) (q = -1, -3) systems favor an endohedral disposition of the doping atom typically in a singlet ground state, with either a 6- or 8-valence electron icosahedral core. For the sake of comparison, the role of the d energy levels in the electronic structure of a variety of doped Au-25(SR)(18)(-1) nanoclusters was investigated for dopant atoms from other families such as Cd, Ag and Pd. Finally, the effect of spin-orbit coupling (SOC) on the electronic structure and absorption spectra was determined. The information in this study regarding the relative energetics of the d-based and super-atom energy levels can be useful to extend our understanding of the preferred doping modes of different transition metals in protected gold nanoclusters.