The evolution of atomic structures and its correlation with the kinetic fragility of liquid tantalum (Ta) during cooling were investigated through molecular dynamics simulations. Pair distribution function, angular distribution function, and largest standard cluster analysis were used to characterize the atomic configurations in the Ta metal system. Results revealed that canonical Kasper clusters with a coordination number of [Formula: see text]12 play a critical role in the formation of Ta monoatomic metallic glasses. Similar to the pattern observed in many multi-component metallic glass-forming liquids, the three-stage evolution pattern of the self-diffusion coefficient could be observed during cooling. The fragile-to-strong (F–S) transition temperature of liquid Ta is identified to be [Formula: see text]. The possible structural reason for the strong-to-fragile liquid transition is correlated with the formation of abundant Kasper medium-range orders (MROs) and their zigzag competition with the loose configurations in liquid regions. The F–S transition is attributed to the success of MROs in the competition and their subsequent rapid growth.

中文翻译：

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原子结构演化及其与液态钽冷却过程中动力学脆性的相关性

通过分子动力学模拟研究了原子结构的演变及其与液态钽 (Ta) 在冷却过程中的动力学脆性的相关性。对分布函数、角分布函数和最大标准聚类分析用于表征 Ta 金属体系中的原子构型。结果表明，配位数为 [公式：见正文]12 的典型 Kasper 簇在 Ta 单原子金属玻璃的形成中起关键作用。类似于在许多多组分金属玻璃形成液体中观察到的模式，在冷却过程中可以观察到自扩散系数的三阶段演变模式。液体 Ta 的脆到强 (F-S) 转变温度被确定为 [公式：见正文]。液体从强到脆转变的可能结构原因与丰富的 Kasper 中程有序 (MRO) 的形成及其与液体区域松散构型的曲折竞争有关。F-S 转变归因于 MRO 在竞争中的成功以及随后的快速增长。