A single hydrogen nanograin has been modeled here to explore the evolution of its structural properties under compression. It is revealed to change from the molecular-insulator (P6₃/mmc) to the molecular-metal phase (Pca2₁) in the form of the hollow spherical shell at a pressure much lower than the one for metallization of bulk hydrogen. The compression is demonstrated to induce both the structure transition and the charge transfer between atoms so that the infrared bands are determined both by the structure and by the atomic-charge distribution. The hydrogen nanograins are, thus, proposed to change more easily from the insulator to metallic hydrogen with respect to bulk hydrogen. Our findings open an alternative route to creating metallic hydrogen.

中文翻译：

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在低压下预测氢纳米颗粒的金属化

这里模拟了单个氢纳米颗粒，以探索其在压缩下的结构特性的演变。结果表明，在比体氢金属化压力低得多的压力下，分子-绝缘体（P6 ₃ /mmc）转变为空心球壳形式的分子-金属相（Pca2 ₁）。压缩被证明会引起原子之间的结构转变和电荷转移，因此红外波段由结构和原子电荷分布决定。因此，相对于体氢，氢纳米颗粒更容易从绝缘体变为金属氢。我们的发现开辟了一条制造金属氢的替代途径。