Excited state dynamics in HgAr2: statistical analysis of vibrational state distribution

Abstract

A quantum mechanical calculation of the vibrational levels of the HgAr₂([graphic omitted]⁺) Van der Waals cluster has been presented and a statistical analysis of the level distribution has been conducted. The theoretical methods are those used by Leitner et al.(J. Chem. Phys., 1981, 91, 3470) for a study of quantum chaos in the Ar₃ cluster. The potential-energy surface is obtained from semiempirical Ar⋯Ar and Ar⋯Hg(³P₁) interactions using appropriate axis switching rotation and electronically adiabatic diagonalization. The vibrational energy levels are calculated by successive diagonalizations and truncations using DVR basis sets in Radau coordinates. The probability distribution of level spacings and the fluctuations of the level positions have been studied and compared with Poisson and Wigner distributions. As for the Ar₃ case studied by Leitner et al., the statistics resemble the Wigner distribution expected for chaotic dynamics and there is very little evidence for regular or intermediate behaviour.