Probing the geometric and electronic structures of the transition metal oxides RhO_n^-1/0 (n = 1-4) clusters

The photoelectron spectroscopies of RhO_n^- (n = 1-2) were obtained via using the photoelectron velocity-map imaging (PE-VMI) approach. The experimental values of the adiabatic detachment energy (ADE) and vertical detachment energy (VDE) for RhO^- were reported to be 1.58 ± 0.02 eV. The experimental AED and VDE values of RhO₂^- were reported to be 2.70 ± 0.02 eV and 2.79 ± 0.02 eV, respectively. The vibrational frequencies of RhO^- and RhO₂^- measured from photoelectron spectra (PES) were 817(76) cm^-1 and 932(55) cm^-1, respectively. Based on the density functional theory (DFT), the RhO_n^-1/0 (n = 1-4) clusters were investigated. The optimized configurations of corresponding ground states and low-lying clusters were discovered. Meanwhile, the simulated photoelectron spectroscopy (PES) of RhO_n^- (n = 1-4) and the theoretical ADE and VDE values of RhO_n^- (n = 1-4) clusters were unveiled to assist future experimental studies of Rhodium oxide clusters. Moreover, the associated molecular orbitals (MOs), natural population analysis (NPA) and bond order analysis have been utilized to investigate the chemical bonding in these groups.