Computer simulation of depolarized light scattering from diatoms with hard core and square well interactions at low temperatures

摘要

We show that the depolarized light scattered from two interacting atoms is qualitatively different for a purely repulsive hard core potential and partially attractive square well potential. This difference is due to the bound states possible with attractive potentials and is used to obtain the spectra from these dimers. The spectra were calculated from the autocorrelation of the scattered electric field found by an effective field model. Values were phase space averaged using Gaussian integration. Molecular dynamics routines evolved the phase space points in time for the autocorrelation. The hard core spectra showed an exponential decay characterized by the mean passage time. The square well spectra consisted of a hard corehyphen;type term, plus a harmonic component due to dimer contributions. Subtraction of the hard core spectra from the square well spectra gave the dimer component. The dimer component of the spectra was proportional to the square of the number of dimers and was characterized by the thermal rotational energy for temperatures below the saturation temperature.