Structural and optical properties of small oxygen-doped- and pure-silver clusters

We present calculations of absorption patterns in large energy intervals fo r the stable structures of oxygen-doped- and pure-silver clusters using the linear-response-type approach which allows one to correlate all II and 6 e lectrons per Ag and O atoms; respectively. For this purpose, we designed a new Ii-electron relativistic effective core potential (11e-RECP) for Ag ato ms at the correlated level of theory, which, together with the associated A O basis set, provide an accurate description of excited states. This has be en evidenced by the comparison of our results with available experimental d ata. We found that inclusion of d electrons in the RECP, as well as in the correlation treatment, is important for an accurate prediction of the compl ete absorption spectra. Moreover, the influence of d electrons of Ag atoms becomes pronounced, even for structural properties of AgnO clusters. Also, the electrons of oxygen are strongly involved in excitations besides those of Ag-valence electrons, leading to intense transitions spread in a large e nergy interval. The role O plays in AgnO clusters differs substantially fro m the one it plays in oxygen-doped alkali clusters, because of the particip ation of the d electrons of Ag atoms.