Chaotic behavior of triatomic clusters

Abstract

The dynamics of triatomic clusters is investigated employing two-body Lennard-Jones and three-body Axilrod-Teller potential functions. Lyapunov exponents are calculated for the total energy range of -2.70 epsilon <E< -0.72 epsilon. The effects of the initial geometry of the cluster, its angular momentum, and the magnitude of three-body interactions are analyzed. It has been found that the dominating factor for the extent of chaotic behavior is the energy assigned to vibrational modes. The introduction of the rotational motion regularizes the dynamics in spite of a higher degree of nonlinearity. The three-body terms in the potential function affect the extent of the chaos in different manners depending on the initial geometry of the cluster. Finally, the time evolution of heterogeneous clusters generated by varying the size, mass, and the interaction strength of a single atom is observed. Their Lyapunov exponent spectra show that the additional nonlinearity reduces the chaotic behavior of the system in most of the cases.