Glassy structures of water were generated by rapidly quenching configurations of 64 and 343 molecules of liquid water. The potential energy was then expanded through quadratic order around local minima generated this way and properties of the resulting harmonic system were calculated. The results were used to test the extent to which the structure of liquid water is similar to that of a harmonic aqueous glass. The radial distribution functions for the glass are remarkably similar to those of the liquid. The vibrational density of states for the glassy water exhibits a gap between 300 and 400 cmminus;1. The normal modes below 300 cmminus;1correspond to molecular translations while the modes above 400 cmminus;1are ascribed to molecular librations. Translational modes are almost entirely responsible for the broadening of oxygenndash;oxygen radial distribution function of the quenched configuration. They are also primarily responsible for the broadening of other radial distribution functions. Vibrational density of states leads to classical and quantum free energies for the harmonic system equal minus;9.62plusmn;0.12 and minus;8.89plusmn;0.12 kcal/mol, respectively, atT=300 K. Both free energies were found to be insensitive to sample size and to the configurational differences between the quenched structures.
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