Infrared spectroscopic study of super-critical water across the Widom line

Samanta, T and Dutta, R and Biswas, R and Bagchi, B (2018) Infrared spectroscopic study of super-critical water across the Widom line. In: Chemical Physics Letters, 702 . pp. 96-101.

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Abstract

When density is varied at a constant temperature just above the gas-liquid critical temperature, the system is found to exhibit large scale density fluctuations which are often rationalized in terms of crossing of a Widom line. We use the discrete variable representation (DVR) scheme to construct the spectroscopic maps for transition frequencies and transition dipoles, and obtain the infrared spectrum of the O-H stretch in the said temperature-density region of the phase diagram. The infrared lineshape shows a crossover from Lorentzian to Gaussian as we approach the Widom line. The width of the lineshape displays a pronounced maximum.

Item Type:	Journal Article
Publication:	Chemical Physics Letters
Publisher:	Elsevier B.V.
Additional Information:	The copyright for this article belongs to the Elsevier B.V.
Keywords:	Infrared spectroscopy, Constant temperature; Critical temperatures; Discrete variable representation; Frequency fluctuation; Infrared spectroscopic studies; Lorentzian-to-gaussian; Transition frequencies; Widom line, Spectroscopic analysis
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	10 Aug 2022 09:59
Last Modified:	10 Aug 2022 09:59
URI:	https://eprints.iisc.ac.in/id/eprint/75510

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