INTRAMOLECULAR DYNAMICS FROM A STATISTICAL-ANALYSIS OF VIBRATIONAL LEVELS - APPLICATION OF 2 COUPLED MORSE OSCILLATOR MODELS TO THE HCN MOLECULE

Two local-mode model Hamiltonians containing stretch-stretch couplings have been utilized to obtain the vibrational energy levels of the HCN molecule for the purpose of studying them statistically. The effect o f the kinetic coupling has been clearly obtained from the statistical analysis which includes nearest-neighbor level-spacing distributions ( NNLSD) and the Delta(3) statistics of Dyson and Mehta. For NNLSD, a pr onounced tendency towards the Wigner distribution has been found. The role of isotopic masses in the statistical properties of the vibration al spectra has also been elucidated. Comparison has been made between the results obtained from the two models. Correlation has been found b etween a transition to chaos (utilizing Poincare sections and Lyapunov exponents) through classical mechanics and the above statistical beha vior of the spectra.