A combined experimental–theoretical study of silver(I) and silver(II) fluorides under high pressure is reported. For Ag^I, the CsCl-type structure is stable to at least 39 GPa; the overtone of the IR-active mode is seen in the Raman spectrum. Its Ag^IIF₂ sibling is a unique compound in many ways: it is more covalent than other known difluorides, crystallizes in a layered structure, and is enormously reactive. Using X-ray diffraction and guided by theoretical calculations (density functional theory), we have been able to elucidate crystal structures of high-pressure polymorphs of AgF₂. The transition from ambient pressure to an unprecedented nanotubular structure takes place via an intermediate orthorhombic layered structure, which lacks an inversion center. The observed phase transitions are discussed within the broader framework of the fluorite → cotunnite → Ni₂In series, which has been seen for other metal difluorides.

中文翻译：

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高达40 GPa的氟化银的高压行为

报道了在高压下对氟化银（I）和氟化银（II）进行的实验理论组合研究。对于Ag ^I，CsCl型结构稳定到至少39 GPa；在拉曼光谱中可以看到红外激活模式的泛音。它的Ag ^II F ₂兄弟姐妹在许多方面都是一种独特的化合物：它比其他已知的二氟化物更共价，在层状结构中结晶，并且具有极大的反应活性。使用X射线衍射并在理论计算（密度泛函理论）的指导下，我们已经能够阐明AgF ₂高压多晶型物的晶体结构。从环境压力到空前的纳米管结构的转变是通过中间的正交各向异性层状结构实现的，该结构缺少反转中心。观察到的相变将在萤石→tun石→Ni ₂系列的更广泛的框架内进行讨论，这在其他金属二氟化物中也可以看到。