Water chemistry coupling frequencies

We have described our most recent efforts to calculate vibrational line shapes for liquid water and its isotopic variants under ambient conditions, as well as to calculate ultrafast observables capable of shedding light on spectral diffusion dynamics, and we have endeavored to interpret line shapes and spectral diffusion in terms of hydrogen bonding in the liquid. Our approach uses conventional classical effective two-body simulation potentials, coupled with more sophisticated quantum chemistry-based techniques for obtaining transition frequencies, transition dipoles and polarizabilities, and intramolecular and intermolecular couplings. In addition, we have used the recently developed time-averaging approximation to calculate Raman and IR line shapes for H20 (which involves... 

Figure 3 A frequency modulation spectrum of the 4z2<-423 transition of HDO near 143 727 MHz, phase coherently detected at twice the modulation frequency and obtained with a synchronously tuned Fabry-Perot cavity cell. This species was present in natural abundance (270 ppm) in a sample of water vapor. The sloping background is due to the nonuniform coupling of the cavity, and may be eliminated by computer analysis. (From Alder JF and Baker JG (2002) Quantitative Millimetre Wavelength Spectroscopy. Cambridge Royal Society of Chemistry reproduced by permission of the Royal Society of Chemistry.)...

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