(37f) Application of An Energy-Conserving Electron-Ion Interaction Model to Radiation Damage in a Lennard-Jones and Binary Lennard-Jones Crystal

Two temperature models are used to model the interaction between the electronic subsystem and the atomic subsystem during thermal transients such as radiation damage, laser heating, and cascade simulations. In this paper, we introduce an energy-conserving version of an inhomogeneous finite reservoir two temperature model using a Langevin thermostat to communicate energy between the two systems. This energy-conserving modification allows the inhomogeneous two temperature model to be used for longer and larger simulations and simulations of small energy phenomena, without introducing non-physical energy fluctuations that may affect the conclusions of the simulation. We test this model on the annealing of a Frenkel defect in a Lennard-Jones crystal. We then consider two idealized models of radiation damage due to a local deposition of heat. We first consider radiation damage in a large Lennard-Jones crystal that readily re-crystallizes. Second we consider radiation damage in a large binary glass-forming Lennard-Jones crystal that retains permanent damage. We find that the electronic subsystem parameters can influence the way heat is transported through the system and have a significant impact on the number of defects after the heat deposition event. We also find that the two model systems have different responses to the electronic subsystem.