Non-equilibrium molecular dynamics simulation trajectories must in principle conserve energy along the entire path. Processes exist in high-energy primary knock-on atom cascades that can affect the energy conservation, specifically during the ballistic phase where collisions bring atoms into very close proximities. The solution, in general, is to reduce the time step size of the simulation. This work explores the effects of variable time step algorithms and the effects of specifying a maximum displacement. The period of the ballistic phase can be well characterized by methods developed in this work to monitor the kinetic energy dissipation during a high-energy cascade.
Revised: April 20, 2011 |
Published: September 1, 2006
Citation
Corrales L.R., and R. Devanathan. 2006.Characterization of Energy Conservation in Primary Knock-On Atom Cascades: Ballistic Phase Effects on Variable Time Steps.Nuclear Instruments and Methods in Physics Research. Section B, Beam Interactions with Materials and Atoms 250, no. 1-2:6-11.PNNL-SA-46662.doi:10.1016/j.nimb.2006.04.075