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

纳米级界面的稳定结构是原子尺度上热活化过程相关动力学的结果。然而，分子动力学（MD）模拟只能跨越非常有限的时间，这阻碍了人们获得完整的力学视图。在这里，我们开发了(1)大规模反应路径分析（NEB）和(2)用于加速原子模拟的转换应变-增强超动力学方法，该方法被发现对于探索集体应力驱动过程（如位错成核）是有效和稳健的。通过引入自适应算法，我们直接获得了压缩铜纳米柱中位错成核的有限温度动态过程，其时间尺度与实验室实验相当。我们的方法为表面位错成核提供了应力和温度相关的激活焓、激活熵和激活体积，而无需事先指导晶体学或变形物理学。

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.