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Articles you may be interested inControl scheme of nonadiabatic transitions with the dynamical shift of potential curve crossing Avoided crossings, conical intersections, and low-lying excited states with a single reference method: The restricted active space spin-flip configuration interaction approach J. Chem. Phys. 137, 084105 (2012); 10.1063/1.4747341Improved results for the excited states of nitric oxide, including the B ∕ C avoided crossingThe correlation diagram of the LiNC/LiCN isomerizing system as a function of ប, taken as a parameter, is considered in conditions of widespread classical chaos. Two series of isolated avoided crossings of very different nature, involving states related by the same 1:8 quantum resonance condition, are characterized and the corresponding interaction matrix elements between adiabatic states analytically calculated and analyzed. One of these series has been found to separate two distinct regions: one for smaller values of ប ͑at any given energy͒ corresponding to regular states, i.e., with a definite nodal pattern, and the other of much more stochastic behavior. Moreover, the 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 resonance. This result constitutes an interpretation of the scarring effect from a new perspective.

Modern spectroscopical techniques allow the efficient experimental investigation of highly excited vibrational states in molecular systems. On the theoretical side, powerful computational methods have also been developed for the calculation of the corresponding energy levels and wave functions, and their interpretation. In this paper we use a combination of two such methods, namely, the distribution of zeroes in the Husimi function and energy-level correlation diagrams, to discuss a classification scheme, for the lowest hundred vibrational levels of the LiNC/LiCN floppy molecular system, based on their dynamical characteristics.

In this paper we numerically check the validity of a theory on the distribution of zeros of the Husimi function due to Leboeuf and Voros ͓J. Phys. A 23, 1765 ͑1990͔͒ for the integrability or chaoticity of a dynamical system in conditions which are not covered in the original proof. Our results for a generic Hamiltonian model for the LiCN molecule indicate also that in this case the conclusions of these authors hold. We have also found that this criterion is related to that proposed by Stratt, Handy and Miller based on the nodal complexity of the wave function ͓J. Chem. Phys. 71, 9911 ͑1979͔͒. Also, for scarred states there is a relation between the positions of the zeros and the fixed points of the Poincaré map corresponding to the scarring periodic orbit, which is the main result of the paper. ͓S1063-651X͑96͒06409-4͔

Correlation diagrams of energy levels using ប as the varying parameter have proven very useful in the characterization of quantum vibrational dynamics of small polyatomic molecules, specially in relation to the transition from order to chaos. In this paper, we present calculations of such correlation diagrams for three molecular systems with very different characteristics, which can be traced down to the topology of their potential energy surfaces. By studying the broad avoided crossings existing in the diagrams, we show that the transition from regular to irregular states always corresponds to a frontier formed by scarred states.