Simulated Dynamics and Endohedral Relesase of Ne from Ne@C60 Clusters

Abstract

Molecular Dynamics (MD) computer simulations are utilized to better understand the escape of neon from small (N=5) endohedral Ne@C60 clusters. Multiple runs at various temperatures are used to increase the reliability of our statistics. The cluster holds together until somewhere between T = 1150K and T = 1200K, where it dissociates, showing no intermediate sign of melting or fullerene disintegration. When the temperature is increased to around T = 4000K, the encapsulated neon atoms begin to leave the cluster, with the fullerene molecules still remaining intact. At temperatures near T = 4400K, thermal disintegration of the fullerenes pre-empts the cluster dissociation. The neon atoms are then more quickly released and the fullerenes form a larger connected structure, with bonding taking place in atom pairs from different original fullerene molecules. Escape constants and half lives are calculated for the temperature range 4000K < T < 5000K. The agreements and disagreements of results of this work with experiments suggest that classical MD simulations are useful in describing fullerene systems at low temperatures and near disintegration, but require more thought and modification before accurately modeling windowing at temperatures below T = 3000K.