The dielectric relaxation of water between 0 degrees C and 35 degrees C

precise complex permittivity data from our laboratory for pure water at tem peratures 0.2 less than or equal to v/degrees C less than or equal to 35 ar e combined with literature results to cover the frequency range 0.2 less th an or equal to v/GHz less than or equal to 410. A description of the <(epsi lon)over cap> (v) spectra requires the superposition of two Debye processes . Nonetheless, relaxation times and dispersion amplitudes discourage the di scussion of the water structure in terms of a two-state model. The interpre tation of the fast process with the relaxation time tau(2) requires additio nal information, whereas it is possible to relate the relaxation time tau(1 ) of the dominating slow process to the production rate of mobile water mol ecules. From the corresponding Eyring free energy, Delta G(not equal), hydr ogen-bond probabilities are deduced, which are in good agreement with data from other methods. (C) 1999 Elsevier Science B.V. All rights reserved.