论文标题
核心水平交叉和电子拓扑转换的可检测性：osmium的情况
Detectability of core level crossing and electronic topological transformations: the case of Osmium
论文作者
论文摘要
最近观察到，在极端压力下，osmium是最不可压缩的金属。声称这些提供了两种不寻常的电子行为的证据：半岩4F和5p水平的交叉以及电子拓扑转换。我们证明，这两种电子现象很容易在密度功能理论中复制和理解，但两者都不会使C/A比与压力的趋势相对。因此，C/A中观察到的异常必须有另一个原因。 osmium也以其高屈服应力而闻名：C/A异常很好地位于Osmium可以支持的差异菌株中。我们提出，在实验数据中，在高偏斜应力下具有强烈优选方向的晶体的机械产率可能会引起观察到的C/A变化。我们讨论了哪些证据仍然是什么证据，即在压力下核心水平重叠可以对任何材料中的晶体结构产生可测量的影响。
Osmium, the least compressible metal, has recently been observed to undergo abrupt changes in the c/a ratio at extreme pressures. These are claimed to provide evidence for two unusual electronic behaviors: a crossing of the semicore 4f and 5p levels, and an electronic topological transition. We demonstrate that these two electronic phenomena are readily reproduced and understood in density functional theory, but that neither perturbs the trend in c/a ratio against pressure. Hence the observed anomalies in c/a must have another cause. Osmium is also notable for its high yield stress: the c/a anomalies lie well within the differential strains which osmium can support. We propose that observed c/a changes can arise from mechanical yield of crystallites with strong preferred orientation under high deviatoric stress in the experimental data. We discuss what evidence remains for the more general hypothesis that core-level overlap under pressure can have measurable effects on the crystal structure in any material.
