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arXiv 1408.1126cond-mat.mtrl-sciphysics.chem-ph
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水和冰的refractive index和电子能隙随压力的增加而增加

The refractive index and electronic gap of water and ice increase with increasing pressure

Ding Pan, Quan Wan, Giulia Galli

摘要:

确定水在高压和高温下的电子和介电性质是了解超临界条件下水环境(例如地球内部)的物理和化学性质的必要先决条件。然而,压缩冰和水的光学测量仍然具有挑战性,并且通常的做法是假设它们的带隙与测量的折射率成反比,这与数百种材料的观察结果一致。在这里,我们报告从头算分子动力学和电子结构计算表明,水和冰的折射率和电子间隙增加与压力,至少高达30 GPa。微妙的电子效应,与带间跃迁的性质和压力下的带边本地化,是负责这种明显的异常行为。

英文摘要:

Determining the electronic and dielectric properties of water at high pressure and temperature is an essential prerequisite to understand the physical and chemical properties of aqueous environments under supercritical conditions, e.g. in the Earth interior. However optical measurements of compressed ice and water remain challenging and it has been common practice to assume that their band gap is inversely correlated to the measured refractive index, consistent with observations reported for hundreds of materials. Here we report ab initio molecular dynamics and electronic structure calculations showing that both the refractive index and the electronic gap of water and ice increase with pressure, at least up to 30 GPa. Subtle electronic effects, related to the nature of interband transitions and band edge localization under pressure, are responsible for this apparently anomalous behavior.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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