标题： 使用无监督机器学习方法研究二十面体准晶体的结构与动力学之间的关系 显示英文标题

标题： Relationship between Structure and Dynamics of an Icosahedral Quasicrystal using Unsupervised Machine Learning

摘要： 我们对一个自组装成二十面体准晶体（IQC）的一组分模型系统的结构、形成和动力学进行了全面研究。 通过结合分子动力学模拟与无监督机器学习技术，我们识别并表征了IQC的独特结构特征，包括二十面体和十二面体排列，并量化了IQC形成过程中局部环境的演变。 我们的分析表明，IQC的形成是由特定局部团簇的出现所驱动的，这些团簇是完全发展的准晶相的前驱体。 此外，我们在不同温度下研究了系统的动力学，识别了从振动受限运动到激活扩散的转变，并揭示了准晶态固有的动态异质性的特征。 为了直接连接结构和动力学，我们使用基于机器学习的序参数来量化不同温度下不同局部环境的存在。 我们发现，由特定机器学习类别捕获的高结构有序区域与抑制的自扩散和最小的动力学异质性相关，这与IQC内的类似相位运动一致。 相反，结构有序度较低的区域表现出增强的集体运动和增加的动力学异质性。 这些结果建立了一个定量框架，用于理解准晶体中结构组织与动力学过程之间的耦合，为IQC稳定性和动力学的机制提供了新的见解。 显示英文摘要

摘要： We present a comprehensive study of the structure, formation, and dynamics of a one-component model system that self-assembles into an icosahedral quasicrystal (IQC). Using molecular dynamics simulations combined with unsupervised machine learning techniques, we identify and characterize the unique structural motifs of IQCs, including icosahedral and dodecahedral arrangements, and quantify the evolution of local environments during the IQC formation process. Our analysis reveals that the formation of the IQC is driven by the emergence of distinct local clusters that serve as precursors to the fully developed quasicrystalline phase. Additionally, we examine the dynamics of the system across a range of temperatures, identifying transitions from vibrationally restricted motion to activated diffusion, and uncovering signatures of dynamic heterogeneity inherent to the quasicrystalline state. To directly connect structure and dynamics, we use a machine-learning-based order parameter to quantify the presence of distinct local environments across temperatures. We find that regions with high structural order, as captured by specific machine-learned classes, correlate with suppressed self-diffusion and minimal dynamical heterogeneity, consistent with phason-like motion within the IQC. In contrast, regions with lower structural order exhibit enhanced collective motion and increased dynamical heterogeneity. These results establish a quantitative framework for understanding the coupling between structural organization and dynamical processes in quasicrystals, providing new insights into the mechanisms governing IQC stability and dynamics.