Department of Chemistry and Applied Biosciences, ETH Zürich, Zürich, Switzerland.
Phys Rev Lett. 2012 Mar 16;108(11):115701. doi: 10.1103/PhysRevLett.108.115701. Epub 2012 Mar 13.
X-ray diffraction experiments have shown that sodium exhibits a dramatic pressure-induced drop in melting temperature, which extends from 1000 K at ~30 GPa to as low as room temperature at ~120 GPa. Despite significant theoretical effort to understand the anomalous melting, its origins are still debated. In this work, we reconstruct the sodium phase diagram by using an ab initio quality neural-network potential. Furthermore, we demonstrate that the reentrant behavior results from the screening of interionic interactions by conduction electrons, which at high pressure induces a softening in the short-range repulsion.
X 射线衍射实验表明，钠在压力下的熔点显著降低，从约 30 GPa 的 1000 K 降低到约 120 GPa 的室温。尽管理论上已经做出了很大的努力来理解这种异常的熔化现象，但它的起源仍存在争议。在这项工作中，我们使用了基于第一性原理的高质量神经网络势来重建钠的相图。此外，我们还证明了再进入行为是由传导电子屏蔽离子间相互作用引起的，这种屏蔽在高压下导致了短程排斥力的软化。
