MONTE CARLO SIMULATION OF CHROMOPHORE FREQUENCY SHIFTS IN RARE GAS MATRICES

Abstract

When a chromophore is trapped inside a rare gas matrix, its characteristic vibrational frequencies are displaced from those of the free molecule. The resulting shifted infrared spectrum depends on both the temperature and the nature of the vacancy site occupied by the chromophore. Combining Monte-Carlo averaging techniques with both a realistic model for the chromophore-matrix interaction and a means of estimating the frequency shifts allows us to examine the effect of temperature and the size and shape of the trapping site on the predicted spectrum. This paper describes the application of this approach to the case of $SF_{6}$ in an Ar matrix.