New Directions in the Study of Ice and Water Clusters

Ohio State University Research Foundation -Do Not Use, Columbus OH

Investigators

Abstract

Sherwin Singer of the Ohio State University is supported by the Theoretical and Computational Chemistry Program to study a wide range of aqueous systems, from small water clusters to bulk water and ice, using both analytical and numerical theoretical methods. One unifying thread in this research is the analysis of water structures in terms of the topology of the hydrogen bond network. Working with the hydrogen bond topology yields analytical results for systems where only numerical simulations would seem feasible. Moreover, the analytical approach allows extraction of hydrogen bonding properties from small water clusters or ice unit cells and, in a very general fashion, application of these parameters to systems large enough for statistical simulations. In this way, the results of high level ab initio calculations on small systems can be extended to predict statistical properties in the thermodynamic limit. Statistical simulations will also be performed with empirical potentials, including the PI's own dissociating water model. Other plans include checks on the performance of empirical potentials with ab initio studies, quantum Monte Carlo studies of vibrational motion, and development of new ab initio molecular dynamics methods. Modeling the behavior of biological molecules, systems in atmospheric chemistry, or pollutants in the ground water requires accurate models for liquid water, ice, and water clusters. The models for liquid water that exist are in need of improvements, which will result from the outcomes of this research.