Computational simulation provides an effective way of understanding the disordered structure and structure-property relationships for metallic glass systems. Here, we systematically investigated the finite-size effects of the static structure and dynamical behaviors in a three-dimensional Cu₅₀Zr₅₀ model metallic glass via classical molecular dynamics (MD) simulations. It was found that the local structure is insensitive to the system size while the dynamical properties present evident finite-size effects. The decoupling between local structure and relaxation dynamics in the investigated supercooling emerges when the system contains less than ∼2000 atoms. However, the collapse can be observed between the structural relaxation time and the dynamical heterogeneity for different sized systems across the whole range of our investigation. Our results support the intrinsic link between the structural relaxation time and dynamic heterogeneity and reveal the critical simulated system size for representing the structural origins of dynamics in bulk metallic glass with ignorable surface effects.

计算仿真为理解金属玻璃系统的无序结构和结构-特性关系提供了一种有效的方法。在这里，我们系统地研究的静态结构的有限尺寸效应和动力学行为在一个三维的Cu ₅₀ Zr的₅₀模型金属玻璃通过经典分子动力学（MD）模拟。发现局部结构对系统大小不敏感，而动力学特性表现出明显的有限大小效应。当系统包含的原子数少于2000时，在研究的过冷中局部结构与弛豫动力学之间就会发生解耦。但是，在我们研究的整个范围内，对于不同大小的系统，可以观察到结构弛豫时间与动力学异质性之间的崩溃。我们的结果支持了结构弛豫时间和动态异质性之间的内在联系，并揭示了关键的模拟系统尺寸，用于代表具有可忽略表面效果的大块金属玻璃动力学的结构起源。