Theoretical study of the low-lying electronic states of ruthenium trimer (Ru_3)

摘要

Several low-lying electronic states of the ruthenium trimer (Ru_3) were investigated by complete active space multiconfiguration self-consistent field and multireference singles and doubles configuration interaction (MRSDCI) methods that included up to 45 million configurations. Two nearly degenerate states, namely, ~(11)B_1 and ~(11)B_2 states were found as candidates for the ground state at lower level of theory. At the highest MRSDCI level, the ~(11)B_1 state was found to be the ground state of Ru_3. The atomization energy of this state was further determined with extensive large-scale MRSDCI calculations. Our calculations facilitate assignment of the recently observed resonance Raman spectra of Ru_3 in Ar matrix by Lombardi and co-workers.