AVOIDED CROSSINGS, SCARS, AND TRANSITION TO CHAOS

The correlation diagram of the LiNC/LiCN isomerizing system as a funct ion of (h) over bar, taken as a parameter, is considered in conditions of widespread classical chaos. Two series of isolated avoided crossin gs of very different nature, involving states related by the same 1:8 quantum resonance condition, are characterized and the corresponding i nteraction matrix elements between adiabatic states analytically calcu lated and analyzed. One of these series has been found to separate two distinct regions: one for smaller values of (h) over bar (at any give n energy) corresponding to regular states, i.e., with a definite nodal pattern, and the other of much more stochastic behavior. Moreover, th e effect of the interaction involved in these avoided crossings is to mix the regular wave functions giving rise to wave functions strongly scarred by the periodic orbits of the associated 1:8 classical resonan ce. This result constitutes an interpretation of the scarring effect f rom a new perspective. (C) 1997 American Institute of Physics.