ISOTOPIC MASS AS DISCRETE CONTROL VARIABLE IN CHAOTIC PROCESSES - THECASE OF MOLECULAR VIBRATIONS

The dynamics of CO2 and HCN molecules are studied with isotopic mass a s a control variable thereby introducing a discrete control variable i n chaos theory. An interesting variation of threshold energy for chaos is obtained with computation of Poincare sections and Lyapunov expone nt. On extending the mass range beyond these two molecules, highly non -monotonic behaviour (with various maxima and minima) for the threshol d energy is found. The quantal correspondence is explored with NNLSD, Dyson-Mehta statistics and correlation coefficients. A correlation bet ween symmetry (brought about with the isotopic mass variation) and the transition from Poisson distribution to Wigner-Dyson distribution is found for the CO2 molecule.