Dynamical Accuracy of Water Models on Supercooling
Journal article, 2020

Molecular dynamics (MD) simulations are commonly used to explore the structural and dynamical properties of supercooled bulk water in the so-called "no man's land" (NML) (150-227 K), where crystallization occurs almost instantaneously. This approach has provided significant insight into experimentally inaccessible phenomena. In this paper, we compare the dynamics of simulations using one-, three-, and four-body water models to experimentally measured quasielastic neutron scattering spectra. We show that the agreement between simulated and experimental data becomes substantially worse with a decrease in temperature toward the deeply supercooled regime. It was found that it is mainly the nature of the local dynamics that is poorly reproduced, as opposed to the macroscopic properties such as the diffusion coefficient. This strongly implies that the molecular mechanism describing the water dynamics is poorly captured in the MD models, and simulated structural and dynamical properties of supercooled water in NML must be interpreted with care.

Author

Thomas O. Farmer

STFC Rutherford Appleton Laboratory

Anders J. Markvardsen

STFC Rutherford Appleton Laboratory

Thomas H. Rod

Data Management and Software Center of the European Spallation Source

Heloisa N. Bordallo

European Spallation Source (ESS)

University of Copenhagen

Jan Swenson

Chalmers, Physics, Nano and Biophysics

Journal of Physical Chemistry Letters

1948-7185 (eISSN)

Vol. 11 18 7469-7475

A New Method to Model the Dynamic Structure Factor by Molecular Dynamics Simulations

Swedish Research Council (VR), 2017-01-01 -- 2020-12-31.

Subject Categories

Physical Chemistry

Theoretical Chemistry

Condensed Matter Physics

DOI

10.1021/acs.jpclett.0c02158

PubMed

32787304

More information

Latest update

11/9/2020