Probing the geometries and electronic properties of iridium-doped silicon $\mathrm{Ir}_{2}\mathrm{Si}_{n} (n=1-18)$ clusters

The effect of double Ir atoms doping on the geometries and electronic properties of silicon clusters has been studied in detail using the density functional theory at B3LYP level. Compared with silicon clusters, the geometric structures of the ground state \( {\rm Ir}_{2}{\rm Si}_{n}\) clusters show different appearance except for Ir2Si8 . The analysis of stability revealed that Ir2Si6, Ir2Si9 and Ir2Si11 have more stable features in all studied clusters and the doping of Ir atoms makes the stabilities of \( {\rm Si}_{n}\) clusters decrease. The analysis of internal charge transfer shows that the Ir atoms always possess negative charge and strong spd hybridization exists in the Ir atoms. The results of electrostatic potential indicates that a negative potential surrounds Ir atoms. Finally, the infrared and Raman spectrums of Ir2Si6,9,11 clusters are discussed.