H. H. Li. Refractive index of alkali halides and its wavelength and temperature derivatives. J. Phys. Chem. Ref. Data5, 329-528 (1976) and references therein. * Sellmeier formula derivation is based on a single data point and knowledge of the dielectric constants and the characteristic absorption peaks.
Lithium iodide (LiI) is a compound that forms white, hygroscopic deliquescent crystals. In the context of optics, lithium iodide is known for its wide transmission range in the infrared spectrum. Because of its hygroscopic nature, it must be handled carefully to prevent moisture absorption, which could degrade its optical properties. LiI is less commonly used than some other alkali halides, like potassium bromide (KBr) or sodium chloride (NaCl), for infrared spectroscopy applications. However, it can still be found in specialized optical systems and sensors where its specific properties are needed.