On the finite temperature red shift in Ar12–HF: can isomerizations in clusters be observed by spectroscopy?

We carry out a set of classical canonical and Fourier path integral simulations to obtain the finite temperature red shift of Ar12–HF. We obtain two approximate estimators for the red shift based on Monte Carlo methods. Our results show a pronounced dependence of the red shift on temperature and isomerizations. The quantum effects on the red shift are substantial even at relatively elevated temperatures.