Theoretical study of structural and optical properties of small silver and gold clusters at defect centers of MgO

In this contribution we present the structural and optical properties of small noble‐metal clusters at the FS‐center defect of the MgO (100) support. We focus on comparing absorption and emission properties of supported silver and gold clusters. It will be shown that the leading absorption features in the low energy regime are similar for supported silver and gold clusters of the same size, in spite of the direct involvement of d electrons from Au atoms due to strong relativistic effects. Molecular dynamics (MD) simulations in the excited electronic states allow us to unravel relaxation mechanism and to propose the smallest noble‐metal clusters at the FS‐center defect, Ag2,4@F5c and Au2,4@F5c, as good candidates for emissive centers. In contrast, larger supported Ag8@F5c and Au8@F5c clusters are unlikely to fluoresce.