Near-i.r. Absorption of H2O and D2O in the Liquid and Supercooled Range

Results are reported on near-i.r. absorption spectra of H2O and D2O down to the temperature region of supercooled liquid. No anomalous behaviour is observed when the absorbance at any given frequency is studied as a function of temperature. A critical-exponent behaviour strikingly correlated with that exhibited by transport properties is instead observed when spectral deconvolution methods are used. Results are discussed in relation with current views on water structure, based on molecular-dynamics simulation results and connectivity calculations