Hydrogen is rarely observed as a ligand in hypervalent species, however, we find that high-pressure hydrogenation may stabilize hypervalent hydrogen-rich materials. Focusing on ternary silicon hydrides via lithium doping, we find anions composed of hypervalent silicon with H ligands formed under high pressure. Our results reveal two different hypervalent anions: layered ${\mathrm{SiH}}_5{}^{-}$ and tricapped triangular prismatic ${\mathrm{SiH}}_6{}^{2-}$. These differ from octahedral ${\mathrm{SiH}}_6{}^{2-}$ described in earlier studies. In addition, there are further hydrogen-rich structures, ${\mathrm{Li}}_3{\mathrm{SiH}}_{10}$ and ${\mathrm{Li}}_2{\mathrm{SiH}}_{6+\delta }$, which may be stabilized at high pressure. Our work provides pointers to future investigations on hydrogen-rich materials.

中文翻译：

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高压下通过锂的三元超价氢化硅

氢很少被视为高价物种中的配体，但是，我们发现高压氢化可以稳定高价富氢材料。重点关注通过锂掺杂的三元氢化硅，我们发现了由高价硅和高压下形成的H配体组成的阴离子。我们的结果揭示了两种不同的高价阴离子：${\mathrm{硅氢}}_5{}^{-}$ 和三边形三棱柱 ${\mathrm{硅氢}}_6{}^{2-}$。这些不同于八面体${\mathrm{硅氢}}_6{}^{2-}$在较早的研究中有描述。此外，还有其他富氢结构，${里}_3{\mathrm{硅氢}}_{10}$ 和 ${里}_2{\mathrm{硅氢}}_{6+\delta }$，可以在高压下稳定下来。我们的工作为将来对富氢材料的研究提供了指导。