Cryolite, Na₃[AlF₆], is essential to commercial aluminium production because alumina is readily soluble in molten cryolite. While the liquid state has been extensively investigated, the spectroscopy of the solid state has been largely ignored. In this paper, we show that the structure at 5 K is the same as that at room temperature. We use a combination of infrared and Raman spectroscopies together with inelastic neutron scattering (INS) spectroscopy. The use of INS enables access to all of the modes of Na₃[AlF₆], including those that are forbidden to the optical spectroscopies. Our spectral assignments are supported by density functional theory calculations of the complete unit cell.

中文翻译：

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冰晶石 Na3AlF6 的结构和振动光谱

冰晶石 Na ₃ [AlF ₆ ] 对于商业铝生产至关重要，因为氧化铝很容易溶于熔融冰晶石中。虽然已经对液态进行了广泛的研究，但固态的光谱学在很大程度上被忽略了。在本文中，我们证明了 5 K 下的结构与室温下的结构相同。我们结合使用红外和拉曼光谱以及非弹性中子散射 (INS) 光谱。使用 INS 可以访问 Na ₃ [AlF ₆ ] 的所有模式，包括那些被禁止使用光谱的模式。我们的光谱分配得到完整晶胞的密度泛函理论计算的支持。