The Lyapunov analysis of the highly excited bend motion of acetylene

The Lyapunov exponents are calculated for the trajectories in the quantum p hase space of the eigenstates of the highly excited C-H bend motion of acet ylene. For a state, if there is only one Lyapunov exponent, the correspondi ng dynamics is ergodic. Quite often, there are the cases that the Lyapunov exponents for a state span a wide spectrum. This means that the motion cann ot be ergodic. Stable and unstable periodic trajectories and the transition between the regions in the quantum phase space with various degrees of irr egularity are also identified, showing that the dynamical structure is quit e complex. (C) 2001 Elsevier Science B.V. All rights reserved.