Molecular Dynamics Simulations of Ice / Water Interfaces

                 

Principal Investigator

Anthony Haymet

School of Chemistry,

University of Sydney

Co-investigators

Jennifer Hayward

Andrew Eaton

School of Chemistry

University of Sydney

Projects

g59 - VPP

Studies of ice / water interfaces at the molecular level
are important for understanding processes such as
melting and freezing, nucleation, and are the first step towards examining the impact of various sized solutes in an ice / water interface. In this project we have performed molecular dynamics (MD) simulations on four ice / water interfaces: basal, prism, [2021], and [2110]. We have calculated many properties of these systems to try to determine the differences between the four faces.
   
             

     
             
                 

What are the results to date and the future of this work ?

Our MD code has undergone much testing and refinement in consultation with ANUSF staff, and is 99 % vectorised. We have generated several versions of the code which handle the different aspects of each of our systems. These versions include the ability to simulate in both the NPT and NVE ensembles in cells of flexible sizes, and the calculation of a wide range of thermodynamic properties.

Simulations have been completed on the four ice / water interfaces, and we are now in the process of analysing the five order parameters - translational, average density, orientational, diffusion, and hydrogen bonding - that characterise these interfaces, and from this hope to determine at a molecular level the differences between the interfaces that have been observed with experiment.

What computational techniques are used ?

Our MD code solves first order differential equations (Hamilton's equations of motion) using a fifth value Gear Predictor Corrector algorithm. Long-range electrostatic interactions are handled using the Ewald summation method.

Publications

J A. Hayward and A. D. J. Haymet, Molecular Dynamics Simulations of the Basal, Prism, and [2021] Ice-1h / Water Interfaces. Poster presentation at the Physics of Liquids conference held in September 1998 in Austria.

                 
- Appendix B