Contemporary materials science research is heavily conducted in silico, involving massive simulations of the atomic-scale evolution of materials. Cataloging basic patterns in the atomic displacements is key to understanding and predicting the evolution of physical properties. However, the combinatorial complexity of the space of possible transitions coupled with the overwhelming amount of data being produced by high-throughput simulations make such an analysis extremely challenging and time-consuming for domain experts. The development of visual analytics systems that facilitate the exploration of simulation data is an active field of research. While these systems excel in identifying temporal regions of interest, they treat each timestep of a simulation as an independent event without considering the behavior of the atomic displacements between timesteps. We address this gap by introducing LAMDA, a visual analytics system that allows domain experts to quickly and systematically explore state-to-state transitions. In LAMDA, transitions are hierarchically categorized, providing a basis for cataloging displacement behavior, as well as enabling the analysis of simulations at different resolutions, ranging from very broad qualitative classes of transitions to very narrow definitions of unit processes. LAMDA supports navigating the hierarchy of transitions, enabling scientists to visualize the commonalities between different transitions in each class in terms of invariant features characterizing local atomic environments, and LAMDA simplifies the analysis by capturing user inputs through annotations. We evaluate our system through a case study and report on findings from our domain experts.

翻译：当代材料科学研究大量采用计算机模拟方法，涉及材料原子尺度演化的大规模仿真。对原子位移基本模式进行系统分类是理解和预测物理性质演化的关键。然而，可能存在的状态跃迁空间具有组合复杂性，加之高通量模拟产生的海量数据，使得领域专家进行此类分析极具挑战性且耗时费力。开发促进模拟数据探索的可视化分析系统已成为当前研究热点。现有系统虽能有效识别时间维度上的关注区域，但将模拟的每个时间步视为独立事件，未考虑时间步之间原子位移的动态行为。为填补这一空白，我们提出LAMDA可视化分析系统，使领域专家能够快速系统地探索状态间跃迁过程。LAMDA采用层次化跃迁分类方法，为位移行为编目提供基础框架，并支持从宏观定性跃迁类别到微观单元过程定义的多分辨率模拟分析。该系统支持在跃迁层次结构中进行导航，使科研人员能够通过表征局部原子环境的不变特征可视化各类跃迁间的共性规律，同时通过标注功能捕获用户输入以简化分析流程。我们通过案例研究评估系统性能，并汇报领域专家的使用反馈。