Metadyancmis based searching for the stable structure of nano-scale interfaces and its application to the evaluation for their adhesion properties

纳米尺度界面的稳定结构是原子尺度上与热激活过程相关的动力学的结果。然而，分子动力学(MD)模拟只能跨越非常有限的时间，这阻碍了人们对力学的全面了解。在这里，我们发展了(1)大规模反应路径分析(NEB)和(2)加速原子模拟的相变应变-Boost超动力学方法，该方法被发现对于探索集体应力驱动的过程，如位错成核，是有效和稳健的。通过引入一种自适应算法，我们直接获得了与实验室实验相当的压缩铜纳米柱位错形核的有限温度动力学过程。我们的方法提供了与应力和温度相关的表面位错成核的活化热、活化熵和活化体，而不需要事先提供关于结晶学或形变物理的指导。

The stable structures of nano-scale interfaces are the results of the kinetics associated with thermally activated processes at the atomic scale. However, molecular dynamics (MD) simulations can only span a very limited time which hinders one from gaining full view of the mechanics. Here, we have developed (1) large scale reaction pathway analysis (NEB) and (2) a transformation strain-boost hyperdynamics method for accelerating atomistic simulations, which is found to be efficient and robust for exploring collective stress-driven processes like dislocation nucleation. By introducing an adaptive algorithm, we directly access the finite-temperature dynamical process of dislocation nucleation in compressed Cu nano-pillar over timescale comparable to laboratory experiments. Our method provides stress- and temperature-dependent activation enthalpy, activation entropy and activation volume for surface dislocation nucleation with no prior guidance about crystallography or deformation physics.