发表机构
Jilin University; Beihang University（吉林大学; 北京航空航天大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
提出基于配位数和原子间距离的轨道耦合模型，统一量化bcc金属中氢与各类缺陷的相互作用，揭示非常规s-d耦合规则，并预测氢脱附双峰分布，助力耐氢材料设计。
AI 中文摘要
氢-缺陷相互作用控制着体心立方（bcc）金属的性能。然而，缺陷之间的复杂差异导致了各种经验模型，这些模型缺乏跨缺陷的迁移性。在此，我们提出了一种基于配位数和原子间距离的轨道耦合模型，该模型量化了bcc金属中纳米空洞、空位环和晶界处的氢溶解能，甚至能预测氢在纳米空洞处的势能面。我们的模型揭示了缺陷受限环境中一种非常规的s-d耦合规则：氢-金属相互作用表现出独特的配位数依赖规律，而氢-氢相互作用则偏离通常推测的s-s耦合，获得了氢-金属耦合的距离衰减规律。这一非常规规则被证明对于重现实验观察到的氢脱附双峰分布至关重要。因此，我们的基于电子结构起源的统一模型对于理解约束下化学键的本质以及工程化耐氢材料至关重要。
英文摘要
Hydrogen-defect interactions control the performance of body-centered-cubic (bcc) metals. However, the complex variations among defects lead to various empirical models that lack transferability across defects. Here, we propose an orbital-coupling model, built on coordination number and interatomic distance, that quantifies the H solution energetics across nanovoids, vacancy loops and grain boundaries in bcc metals, and even predicts the potential-energy surfaces of H at nanovoids. Our model reveals an unconventional s-d coupling rule in the confined environment of defects: H-metal interactions exhibit a unique coordination-dependent law, whereas H-H interactions, deviating from the usually speculated s-s coupling, acquire the distance-decay law of H-metal coupling. This unusual rule proves essential to reproduce the experimentally observed bimodal profile of H desorption. Our electronic-structure-origin, unified model is thus crucial to understanding the nature of chemical bonds under constraint and engineering the H-tolerant materials.
