Cao Penghui, Li Minghai, Heugle Ravi J, Park Harold S, Lin Xi
Department of Mechanical Engineering and Division of Materials Science and Engineering, Boston University, Boston, MA 02215, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2012 Jul;86(1 Pt 2):016710. doi: 10.1103/PhysRevE.86.016710. Epub 2012 Jul 24.
A generic history-penalized metabasin escape algorithm that contains no predetermined parameters is presented in this work. The spatial location and volume of imposed penalty functions in the configurational space are determined in self-learning processes as the 3N-dimensional potential energy surface is sampled. The computational efficiency is demonstrated using a binary Lennard-Jones liquid supercooled below the glass transition temperature, which shows an O(10(3)) reduction in the quadratic scaling coefficient of the overall computational cost as compared to the previous algorithm implementation. Furthermore, the metabasin sizes of supercooled liquids are obtained as a natural consequence of determining the self-learned penalty function width distributions. In the case of a bulk binary Lennard-Jones liquid at a fixed density of 1.2, typical metabasins are found to contain about 148 particles while having a correlation length of 3.09 when the system temperature drops below the glass transition temperature.
本文提出了一种不含预定参数的通用历史惩罚元盆地逃逸算法。在对3N维势能面进行采样时,通过自学习过程确定构型空间中施加惩罚函数的空间位置和体积。利用低于玻璃化转变温度的二元 Lennard-Jones 液体证明了该算法的计算效率,与之前的算法实现相比,整体计算成本的二次缩放系数降低了O(10(3))。此外,作为确定自学习惩罚函数宽度分布的自然结果,获得了过冷液体的元盆地大小。对于固定密度为1.2的二元 Lennard-Jones 体相液体,当系统温度降至玻璃化转变温度以下时,典型的元盆地包含约148个粒子,相关长度为3.09。