Time-dependent density functional study of absorption spectra of small bimetallic silver-nickel clusters

The absorption spectra of small bimetallic Ag_mNi_p (5 ≤ m + p ≤ 8) clusters are investigated in the framework of the time-dependent density functional theory (TDDFT). The absorption spectra of small bimetallic Ag_mNi_p clusters are broadened, and blue-shifted with increasing nickel proportion as compared to Ag_m clusters. The excitation energies, oscillator strengths, and dominant molecular orbital transitions are calculated to understand the transition processes of electrons and the properties of absorption spectra, in particular the evolution of the resonance band with the Ag/Ni composition and the spatial positions of nickel atoms.