Accelerated molecular dynamics and equation-free methods for simulating diffusion in solids.

Deng, Jie ; Zimmerman, Jonathan A. ; Thompson, Aidan Patrick ; Brown, William Michael (Oak Ridge National Laboratories, Oak Ridge, TN) ; Plimpton, Steven James ; Zhou, Xiao Wang ; Wagner, Gregory John ; Erickson, Lindsay Crowl

关键词: AGING;    DIFFUSION;    MOLECULAR DYNAMICS METHOD;    PERFORMANCE;    SIMULATION;    SYNTHESIS;   

DOI  :  10.2172/1030307
RP-ID  :  SAND2011-6659
PID  :  OSTI ID: 1030307
Others  :  TRN: US201201%%292

学科分类：材料科学（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

Many of the most important and hardest-to-solve problems related to the synthesis, performance, and aging of materials involve diffusion through the material or along surfaces and interfaces. These diffusion processes are driven by motions at the atomic scale, but traditional atomistic simulation methods such as molecular dynamics are limited to very short timescales on the order of the atomic vibration period (less than a picosecond), while macroscale diffusion takes place over timescales many orders of magnitude larger. We have completed an LDRD project with the goal of developing and implementing new simulation tools to overcome this timescale problem. In particular, we have focused on two main classes of methods: accelerated molecular dynamics methods that seek to extend the timescale attainable in atomistic simulations, and so-called 'equation-free' methods that combine a fine scale atomistic description of a system with a slower, coarse scale description in order to project the system forward over long times.