Ro-vibrational Raman Cross Sections of Water Vapor in the OH Stretching Region

16 pages, 6 figures, 7 tables.The Raman spectrum of H2O, in the gas phase at 26 mbar and 295 K, has been recorded from 3400 to 4130 cm−1 using an improved spectrometer of very high sensitivity. This spectrum is analyzed in terms of the wavefunctions and energy levels of Flaud and Camy-Peyret [J. Mol. Spectrosc. 51, 142 (1974)], and of the polarizability derivatives with respect to the dimensionless normal coordinates q1 and q3. It is shown that the anharmonic coupling between the vibrational states ν1 and ν3 has to be considered for a correct simulation of the observed spectrum. Tables with scattering strengths and energies of ro-vibrational transitions are provided in order to simulate the Raman spectrum of water vapor over a broad range of temperatures, from few Kelvin, under supersonic expansions, to high temperature, in combustion processes.the Spanish DGICYT for financial support (Research Projects PB 91-0133 and PB 94-1526).Peer reviewe