Simulation of the Growth and Decay of Isolated Lennard–Jones Clusters

Molecular dynamics simulations of isolated Lennard–Jones clusters were performed. Starting from two atoms with total energy E, atoms are injected at random intervals, consistent with a specified vapour saturation, and simulations are continued until the cluster re-evaporates back to a dimer. The maximum size achieved is recorded. Typically, between 107 and 109 simulations are performed and the fraction of these growing to sizes five and six is determined. This fraction decreases with increasing E, but is much larger than predicted by a treatment based on the capillary approximation. However, the mean energy of the resulting 5-mers and 6-mers is higher than that at equilibrium, indicating that the grown clusters are very unstable.

Keywords Homogeneous nucleation, Lennard–Jones clusters, molecular dynamics