Geometrical and electronic properties of Si_n (n = 6–15) clusters with rhodium impurity: a first-principles investigation

To delve into the microscopic property of the cluster RhSi_n (n = 6–15), this study employs the CALYPSO structure prediction program and density functional theory. The paper conducts a comprehensive theoretical analysis of the clusters, examining parameters such as structures, relative stabilities, charge transfer, vertical electron affinity, vertical ionization potential, chemical potential, chemical hardness, and infrared and Raman spectra. The optimization process reveals that the rhodium doping has clearly changed the structures of silicon clusters. The ground state geometries favor Rh-linked framework beginning from n = 6, and they favor Rh-encapsulated Si cages when n approach 10. RhSi₁₃ cluster is more stable than its neighbors. The charges transfer within the clusters always transfer from silicon atom to rhodium atom, and there is spd hybridization in RhSi_n cluster. The analyzed chemical potential and chemical hardness pointed out the RhSi₁₃ cluster has the stronger hardness than other clusters. At last, the infrared and Raman spectrum properties for RhSi₁₃ cluster are analyzed.