Study of structures, electronic and spectral properties of anionic AuMgn− (n = 2–12) clusters

Abstract

Using CALYPSO code and DFT calculations, the structures, stabilities, electronic and spectral properties of bimetallic AuMg_n⁻ (n = 2–12) are comprehensively studied. It is shown that AuMg_n⁻ clusters evolved from planar configuration to triangular pyramid-base structure, to triangular prism-base empty cage structure, and finally to filled cage motif. Large-sized AuMg_n⁻ clusters are structurally different from their individual Mg clusters, indicating that doping atoms have a greater influence on their structure. The charge transfer from Mg to Au occurs in the AuMg_n⁻ clusters. Stability analysis suggests prominent stability of AuMg₃⁻ and AuMg₉⁻, which have 8 and 18 closed-shell electronic configurations. Bond length calculations show that AuMg₃⁻ and AuMg₉⁻ have a compact structure, meaning that there is a strong atomic interaction. The multi-center bond and Mayer bond order studies indicate a stronger Au–Mg interaction than the Mg–Mg interaction. The spectral properties based on the PES, IR, and Raman spectra have also been discussed.

Graphical abstract