Dynamical Potential Approach To Molecular Highly Excited Vibration

We employ the algebraic method to study the molecular highly excited vibration,especially the dynamics of dissociation and transition states. The dynamical potentialidea is developed, by which DCO highly excited vibration is explored, together withLyapunov exponent and phase space analysis. We also set up a model for bendingtransition state. The algebraic Hamiltonian we used is determined by spectroscopicdata, so the results by this method are closely related to experiments.The conserved polyad number of DCO vibration is employed to classify its highlyexcited vibrational states. The dynamical potentials are shown to be anti-Morse andharmonic along the D-C and C-O coordinates, respectively. These, together with theLyapunov and phase space analysis, are demonstrated to interpret the state stabilitythat in the lower energy realm according to a polyad, D-C is prone to be dissociativeor chaotic while the states in the very high energy realm, are stable and regular. Amodel of a particle moving in an anti-Morse potential and coupled to a simple har-monic oscillator is established for DCO vibrational dynamics. This clarifies the su-perficial complexity of DCO highly excited levels and its dissociation dynamics. Thedynamical potential approach is also applied to other systems such as H2O and DCNand its effectiveness is verified.Bending motion is traditionally described by the Morse oscillator. However, thisis not appropriate for highly excited bending transition states. So we replace the Morseoscillator with pendulum and set up a model of a Morse oscillator (stretching vibra-tion) coupled with a pendulum (bending vibration). Hamiltonian is written down andparameters in the Hamiltonian are discussed.