AI 中文总结
该研究开发核量子修正的机器学习势NQC-PACE，通过巨正则模拟发现α-铁一般晶界处氢偏聚因核量子效应显著增强，为含轻元素量子效应的材料大规模分析提供了方法
AI 中文摘要
原子级描述缺陷处的氢扩散与俘获是理解氢脆的关键。作为金属中最轻的溶质，氢即使在室温下也会表现出改变这些过程的核量子效应。明确处理此类效应的计算成本极高，限制了复杂环境的大规模模拟。本研究采用基于原子簇展开（PACE）高性能实现的Fe-H机器学习原子间势（MLIP），覆盖多种Fe-H环境，并采用300 K下质心约束路径积分分子动力学得到的量子平均力，对支撑其迁移性的训练构型进行重新标记，得到无需额外密度泛函理论计算的核量子修正PACE（NQC-PACE）。与基础PACE相比，NQC-PACE可描述氢在空位、位错、表面及一般晶界处俘获、氢-氢相互作用以及α-Fe中扩散的核量子效应。巨正则蒙特卡洛/分子动力学模拟显示，核量子效应显著增强了一般晶界处的氢偏聚，且俘获行为与实验趋势更吻合；该增强源于对开放、各向异性软局域环境的选择性量子稳定。本框架利用有限温度量子平均力重新标记MLIP覆盖的构型空间，可用于存在轻元素量子效应的复杂材料的大规模分析。
英文摘要
Atomistic descriptions of hydrogen diffusion and trapping at defects are essential for understanding hydrogen embrittlement. As the lightest solute in metals, hydrogen exhibits nuclear quantum effects that alter these processes even at room temperature. Explicit treatment of such effects is computationally demanding, limiting large-scale simulations of complex environments. Here, we use an Fe-H machine-learning interatomic potential (MLIP) based on the performant implementation of the atomic cluster expansion (PACE), covering diverse Fe-H environments, and relabel the training configurations underpinning its transferability with quantum mean forces from centroid-constrained path-integral molecular dynamics at 300 K. This yields a nuclear-quantum-corrected PACE (NQC-PACE) without additional density functional theory calculations. At parent PACE, NQC-PACE describes nuclear quantum effects on hydrogen trapping at vacancies, dislocations, surfaces and general grain boundaries, H-H interactions, and diffusion in alpha-Fe. Grand-canonical Monte Carlo/molecular dynamics simulations show nuclear quantum effects markedly enhance hydrogen segregation at general grain boundaries and trapping behaviour in closer agreement with experimental trends. This enhancement arises from selective quantum stabilisation of open, anisotropically soft local environments. Our framework uses finite-temperature quantum mean forces to relabel the configurational space covered by an MLIP, enabling large-scale analysis of complex materials where light-element quantum effects matter.
