Analysis of the "unusual" vibrational components of triply degenerate vibrational mode nu(6) of Mo(CO)(6) based on the classical interpretation of the effective rotation-vibration Hamiltonian

Relational structure of the triply degenerate vibrational state v(0)(F-1a) of the octahedral molecule Mo(CO)(6) is analyzed qualitatively on the basis of classical mechanics. We show that the energy level redistribution betwe en the vibrational components of v(6)(F-1a) occurs due to rotational excita tion and is related to the formation of singular points of classical rotati onal energy surfaces, The singularity is stable under small variations of p arameters of the effective rovibrational Hamiltonian. Parameters responsibl e for the persistence of this phenomenon are specified, Comparison with qua ntum calculations demonstrates the high qualitative and quantitative accura cy of our classical analysis, (C) 2000 Academic Press.