An ideal glass transition in supercooled water?
Analyzing recent molecular dynamics simulations in deeply supercooled liquid states, we have found that the single particle dynamics in water can be interpreted in terms of Mode Coupling Theory, in its so-called ideal formulation. In this paper we review such evidence and discuss the relevance of this finding for the debated thermodynamic behavior of supercooled water. The experimental apparent power-law behavior of the transport coefficients in water, diverging or going to zero at the so-called Angell temperature could indeed be interpreted as a kinetic, as distinct from thermodynamic, phenomena. This finding removes the need of a thermodynamic singularity for the explanation of the anomalies of liquid water. We also comment on the development of a significant harmonic dynamics on cooling the liquid, which could indicate a transition from a fragile to a strong behavior in liquid water.
KeywordsAnharmonic Oscillation Mode Coupling Theory Supercooled Water Harmonic System Supercooled Liquid State
Unable to display preview. Download preview PDF.
- W. Kob, Ann. Rev. Comp. Physics, Vol III, D. Stauffer Editor, World Scientific 1995.Google Scholar
- C.A. Angell, in Water: A Comprehensive Tretise, Ed. F. Franks (Plenum, New York, 1981), Ch. 1.Google Scholar
- P. G. Debenedetti, Metastable Liquids (Princeton University Press, 1996), in press.Google Scholar
- F. Sciortino, P. Gallo, P. Tartaglia, S. H. Chen, Phys. Rev. E xx, xxxx (1996).Google Scholar
- The SPC/E model is a rigid model with constrains on the oxygen-hydrogen bond and hydrogen-oxygen-hydrogen angle. Thus, each molecule contributes only 6 degree of freedom.Google Scholar
- W. Götze and L. Sjögren, special issue of Chem. Phys on Rate processes with kinetic parameters distributed in time and space Y.A. Berlin, J.R. Miller and A. Plonka Editors, in press (1996)Google Scholar
- C. A. Angell in Relaxations in Complex Systems, edited by K. Ngai and G. B. Wright. (National Technical Information Service, U.S. Dept. of Commerce: Springfield, VA, 1985) p. 1; C. A. Angell, J. Non-Cryst. Solids 13, 131.Google Scholar