More accurate X-ray scattering data of deeply supercooled bulk liquid water

Abstract

Deeply supercooled water droplets held containerless in an acoustic levitator are investigated with high-energy X-ray scattering. The temperature dependence of the X-ray structure function is found to be nonlinear. Comparison with two popular computer models reveals that structural changes are predicted too abrupt by the TIP5P-E model, while the rate of change predicted by TIP4P-Ew is in much better agreement with experiment. The abrupt structural changes, predicted by the TIP5P-E model to occur in the temperature range between 260 and 240 K as water approaches the homogeneous nucleation limit, are unrealistic. Both models underestimate the distance between neighbouring oxygen atoms and overestimate the sharpness of the OO distance distribution.

Keywords:

• supercooled water
• acoustic levitation
• X-ray scattering

Acknowledgements

This work was supported under the following contracts: Subcontract Nos. 4000061892 and 4000067087 to Materials Development, Inc. from UT-Battelle, LLC; and SNS contract No. DE-AC05-00OR22725 for the U.S. Department of Energy and managed by UT-Battelle, LLC. APS, U.S. DOE, Argonne National Laboratory was supported under contract No. DE-AC02-06CH11357.