A molecular dynamics study of model cyanoadamantane

A simple model for the cyanoadamantane molecule is proposed and investigated by molecular dynamics simulation. This model has the three phases (crystalline, plastic and fluid) within temperature ranges corresponding to those observed experimentally. An interesting aspect of the model is that the plastic phase has much faster rotational dynamics (by five orders of magnitude) than the true system. This feature opens the route for a molecular dynamics study of the eventual orientational glassy state, within times accessible to simulation methods. The preliminary study conducted in the present work is focused on the plastic and fluid phases. The static and dynamic properties are calculated for both phases and compared with them and with those accessible by experiment. This study confirms the overall adequacy of the proposed model. The general features found through this analysis reveal the nature of the rotational and translational dynamics in these two phases as well as their underlying differences.