Many materials science phenomena, such as growth and self-organisation, are dominated by activated diffusion processes and occur on timescales that are well beyond the reach of standard-molecular dynamics simulations. Kinetic Monte Carlo (KMC) schemes make it possible to overcome this limitation and achieve experimental timescales. However, most KMC approaches proceed by discretizing the problem in space in order to identify, from the outset, a fixed set of barriers that are used throughout the simulations, limiting the range of problems that can be addressed. Here, we propose a more flexible approach -- the kinetic activation-relaxation technique (k-ART) -- which lifts these constraints. Our method is based on an off-lattice, self-learning, on-the-fly identification and evaluation of activation barriers using ART and a topological description of events. The validity and power of the method are demonstrated through the study of vacancy diffusion in crystalline silicon.
Evaluating approaches for on-the-fly machine learning interatomic potential for activated mechanisms sampling with the activation-relaxation technique nouveau
Negative Strain-Rate Sensitivity in Metallic Glasses Driven by Rejuvenation-Relaxation Competition: Kinetic Monte Carlo Simulations and a Minimal Effective Model
Faculty of Mechanical Engineering, Kanazawa University（金泽大学机械工程学院）；Department of Mechanical Science and Bioengineering, The University of Osaka（大阪大学机械科学生物工程系）；Department of Earth and Space Science, The University of Osaka（大阪大学地球空间科学系）
Solution-phase fluorination of nanodiamond: near-surface NV$^-$ activation and spin relaxation
Óbuda University（欧贝达大学）；HUN-REN Wigner Research Centre for Physics, Institute for Solid State Physics and Optics（匈牙利研究与教育网络维格纳物理研究中心固体物理与光学研究所）；Budapest University of Technology and Economics（布达佩斯技术与经济大学）；HUN-REN Centre for Energy Research, Institute of Technical Physics and Materials Science（匈牙利研究与教育网络能源研究中心技术物理与材料科学研究所）；Kandó Kálmán Faculty of Electrical Engineering, Óbuda University（欧贝达大学坎多·卡尔曼电气工程学院）
Discretized Wiener-Khinchin theorem for Fourier-Laplace transformation: application to molecular simulations
傅里叶-拉普拉斯变换的维纳-欣钦定理（Wiener-Khinchin theorem for the Fourier-Laplace transformation，WKT-FLT）提供了一种从分子模拟中计算任意自相关函数的数值单边傅里叶变换的稳健方法。然而，现有的WKT-FLT方程在频域松弛函数的输出中产生两个伪影。此外，这些伪影在从松弛函数转换的频域响应函数中更明显。我们发现这些文物的来源，与离散化的WKT-FLT方程。考虑到这些来源，我们推导出新的离散WKT-FLT方程指定的频域松弛和响应函数与文物删除。使用的离散WKT-FLT方程示出了一个在飞行算法的流程图。给出了离散化WKT-FLT方程在分子模拟计算动态结构因子和波矢相关动态磁化率中的应用实例。
